A US Patriot missile defence system is pictured during the Israeli-US military exercise "Juniper Cobra" at the Hatzor Airforce Base in Israel on March 8, 2018.
Exercise Juniper Cobra is a five-day combined military exercise between Israel and the United States. 
 / AFP PHOTO / JACK GUEZ        (Photo credit should read JACK GUEZ/AFP/Getty Images)
JACK GUEZ/AFP/Getty Images
A US Patriot missile defence system is pictured during the Israeli-US military exercise "Juniper Cobra" at the Hatzor Airforce Base in Israel on March 8, 2018. Exercise Juniper Cobra is a five-day combined military exercise between Israel and the United States. / AFP PHOTO / JACK GUEZ (Photo credit should read JACK GUEZ/AFP/Getty Images)
Now playing
01:42
IDF: Israel shoots down Syrian fighter jet
The South Korean Air Force said in a press release today that South Koreas four F-15K fighters from Daegu Air Base carried out a joint drill this afternoon with US Air Force's two B-1B bombers from Guam and the US Marine Corps' four F-35B aircraft based in Japan. 

They conducted an air-to-ground bombing drill, which simulates a surgical strike of key enemy facilities, over the Pilseung range in the eastern province of Gangwon. 
 
The South Korean and the US Air Forces carried out a joint air defense exercise this afternoon on Aug. 31 to strongly counter North Koreas relatedly launches of ballistic missiles and development of nuclear weapons.
South Korean Air Force/South Korean Air Force
The South Korean Air Force said in a press release today that South Koreas four F-15K fighters from Daegu Air Base carried out a joint drill this afternoon with US Air Force's two B-1B bombers from Guam and the US Marine Corps' four F-35B aircraft based in Japan. They conducted an air-to-ground bombing drill, which simulates a surgical strike of key enemy facilities, over the Pilseung range in the eastern province of Gangwon. The South Korean and the US Air Forces carried out a joint air defense exercise this afternoon on Aug. 31 to strongly counter North Koreas relatedly launches of ballistic missiles and development of nuclear weapons.
Now playing
00:51
US fighter jets fly over Korean Peninsula
An Israeli F-15 Eagle fighter jet takes off from a Israeli Air Force Base on November 19, 2012, on a mission over the Palestinian Gaza Strip. Israeli air strikes killed 22 Palestinians, hiking the Gaza death toll to 99 as global efforts to broker a truce to end the worst violence in four years gathered pace.  AFP PHOTO / JACK GUEZ        (Photo credit should read JACK GUEZ/AFP/Getty Images)
JACK GUEZ/AFP/AFP/Getty Images
An Israeli F-15 Eagle fighter jet takes off from a Israeli Air Force Base on November 19, 2012, on a mission over the Palestinian Gaza Strip. Israeli air strikes killed 22 Palestinians, hiking the Gaza death toll to 99 as global efforts to broker a truce to end the worst violence in four years gathered pace. AFP PHOTO / JACK GUEZ (Photo credit should read JACK GUEZ/AFP/Getty Images)
Now playing
01:26
US shoots down pro-Syrian regime drone
This picture taken and released by Japan's Defence Ministry on June 11, 2014 and received via Jiji Press shows one of two Chinese Su-27 fighter jets which flew "dangerously" close to two Japanese military planes over the East China Sea. Japan accused China of flying fighter jets "dangerously" close to two of its military planes over the East China Sea on June 11, as bilateral tensions simmer over the countries' territorial dispute. On June 12, Japan summoned the Chinese ambassador to complain about the fighter jets activities.    JAPAN OUT     AFP PHOTO/Defense Ministry via Jiji Press
--- EDITORS NOTE -- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / AFP PHOTO/Defense Ministry via Jiji Press"- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTSJIJI PRESS/AFP/Getty Images
Defense Ministry via Jiji Press/AFP/Getty Images/FILE
This picture taken and released by Japan's Defence Ministry on June 11, 2014 and received via Jiji Press shows one of two Chinese Su-27 fighter jets which flew "dangerously" close to two Japanese military planes over the East China Sea. Japan accused China of flying fighter jets "dangerously" close to two of its military planes over the East China Sea on June 11, as bilateral tensions simmer over the countries' territorial dispute. On June 12, Japan summoned the Chinese ambassador to complain about the fighter jets activities. JAPAN OUT AFP PHOTO/Defense Ministry via Jiji Press --- EDITORS NOTE -- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO / AFP PHOTO/Defense Ministry via Jiji Press"- NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTSJIJI PRESS/AFP/Getty Images
Now playing
00:53
Russian fighter jet flies 5 feet from US plane
f 35 fighter jet thermal scan jnd orig vstan_00003326.jpg
Flir Systems Inc.
f 35 fighter jet thermal scan jnd orig vstan_00003326.jpg
Now playing
00:46
Thermal scan shows F-35 fighter jet in flight
CNN's Clarissa Ward is on board a U.S. Air Force KC-135 refueling Stratotanker, accompanying two U.S. F-22 Raptor fighter jets to Romania.
CNN's Clarissa Ward is on board a U.S. Air Force KC-135 refueling Stratotanker, accompanying two U.S. F-22 Raptor fighter jets to Romania.
Now playing
01:10
How to refuel a fighter jet in midair
Russian flag
Russian flag
Now playing
00:48
Russian fighter jet, US Navy plane have close encounter
F-35A Lightning II's from the 34th Fighter Squadron at Hill Air Force Base, Utah, land at Royal Air Force Lakenheath, England, April 15, 2017. The aircraft arrival marks the first F-35A fighter training deployment to the U.S. European Command area of responsibility or any overseas location as a flying training deployment. (U.S. Air Force photo/Tech. Sgt. Matthew Plew)
US Air Force/Tech. Sgt. Matthew Plew
F-35A Lightning II's from the 34th Fighter Squadron at Hill Air Force Base, Utah, land at Royal Air Force Lakenheath, England, April 15, 2017. The aircraft arrival marks the first F-35A fighter training deployment to the U.S. European Command area of responsibility or any overseas location as a flying training deployment. (U.S. Air Force photo/Tech. Sgt. Matthew Plew)
Now playing
00:55
Watch US F-35 jet fighters arrive in Europe (2017)
Two F-35B Lightning II Joint Strike Fighters complete vertical landings aboard the amphibious assault ship USS Wasp (LHD 1) during the opening day of the first session of operational testing. As the future of Marine Corps aviation, the F-35B will eventually replace all aircraft from three legacy Marine Corps platforms; the AV-8B Harrier, the F/A-18 Hornet, and the EA-6B Prowler. The aircraft are stationed with Marine Fighter Attack Training Squadron 501, Marine Aircraft Group 31, 2nd Marine Aircraft Wing, Beaufort, South Carolina and Marine Fighter Attack Squadron 121, Marine Aircraft Group 13, 3rd Marine Aircraft Wing, Yuma, Arizona. (U.S. Marine Corps photo by Lance Cpl. Remington Hall/Released)
Lance Cpl. Remington Hall/USMC
Two F-35B Lightning II Joint Strike Fighters complete vertical landings aboard the amphibious assault ship USS Wasp (LHD 1) during the opening day of the first session of operational testing. As the future of Marine Corps aviation, the F-35B will eventually replace all aircraft from three legacy Marine Corps platforms; the AV-8B Harrier, the F/A-18 Hornet, and the EA-6B Prowler. The aircraft are stationed with Marine Fighter Attack Training Squadron 501, Marine Aircraft Group 31, 2nd Marine Aircraft Wing, Beaufort, South Carolina and Marine Fighter Attack Squadron 121, Marine Aircraft Group 13, 3rd Marine Aircraft Wing, Yuma, Arizona. (U.S. Marine Corps photo by Lance Cpl. Remington Hall/Released)
Now playing
02:27
The U.S. military's $400B fighter jet (2016)
An F-35A Lightning II gets ready to land Sept. 13, 2013, at Hill Air Force Base, Utah. This was the first F-35 to land at Hill AFB. The multirole, fifth-generation fighter arrived from the 422nd Test and Evaluation Squadron, at Nellis AFB, Nev. to undergo post-production modifications at the Ogden Air Logistics Complex. (U.S. Air Force photo/Alex R. Lloyd)
Alex R. Lloyd/USAF
An F-35A Lightning II gets ready to land Sept. 13, 2013, at Hill Air Force Base, Utah. This was the first F-35 to land at Hill AFB. The multirole, fifth-generation fighter arrived from the 422nd Test and Evaluation Squadron, at Nellis AFB, Nev. to undergo post-production modifications at the Ogden Air Logistics Complex. (U.S. Air Force photo/Alex R. Lloyd)
Now playing
02:19
US delivers F-35 fighter jets to Israel
HELME, ESTONIA - MAY 19:  An F-16 fighter plane of the Royal Danish Air Force simulates an attack during a demonstration while participating in the NATO "Spring Storm" military exercises on May 19, 2014 near Helme, Estonia. The annual exercises, in which Estonian, Latvian, Lithuainian, U.S., British, Polish, Belgian and Danish troops are participating, are underway as sporadic fighting between Ukrainian and pro-Russian separatists continues in eastern Ukraine.  (Photo by Sean Gallup/Getty Images)
Sean Gallup/Getty Images Europe/Getty Images
HELME, ESTONIA - MAY 19: An F-16 fighter plane of the Royal Danish Air Force simulates an attack during a demonstration while participating in the NATO "Spring Storm" military exercises on May 19, 2014 near Helme, Estonia. The annual exercises, in which Estonian, Latvian, Lithuainian, U.S., British, Polish, Belgian and Danish troops are participating, are underway as sporadic fighting between Ukrainian and pro-Russian separatists continues in eastern Ukraine. (Photo by Sean Gallup/Getty Images)
Now playing
00:59
Fighter pilot passes out, jet goes into free fall
(CNN) —  

The Israeli military shot down a Syrian fighter jet after it entered Israeli airspace on Tuesday afternoon, the Israel Defense Forces (IDF) said, raising fears of further military escalation in the region.

The Russian-made Sukhoi jet entered two kilometers into Israeli airspace when two Patriot missiles were launched to intercept the aircraft, the IDF said. The missiles hit the jet once it had crossed back into Syrian airspace, the IDF said, adding that the military did not know what happened to the pilot of the aircraft.

Syria said its jet was conducting an operation against “terrorist groups” when it was hit by Israeli fire, according to a state media report.

“The Israeli enemy targeted one of our warplanes while conducting air raids against these groups in the area of Saida on the outskirts of al-Yarmouk Basin in the Syrian airspace,” a Syrian state TV banner said, quoting a military source.

Yarmouk basin is one of the last remaining areas in southern Syria not yet under government control. Syrian forces, backed by the Russian military, have been carrying out an extensive campaign in the area in recent days, attempting to wrest control from an ISIS affiliate that is clinging on to a small pocket of territory.

Israel said there had been a notable increase in activity by the Syrian military in the area on Tuesday, especially the Syrian air force, as a result of ongoing internal fighting in the war-torn country.

The jet took off from the T-4 military base northeast of Damascus, according to IDF spokesman Lt. Col. Jonathan Conricus. Israel has struck the T-4 base multiple times in the last year, targeting what the Israeli military has said are Iranian military assets at the base.

Before it launched its strike, Israel communicated with Russia to make sure the jet was Syrian, and not part of the Russian air force, according to Conricus. So-called “deconfliction measures” have been in place between the two countries since Russian forces entered Syria on behalf of President Bashar al-Assad.

The jet was either a Sukhoi 22 or Sukhoi 24, the IDF said Tuesday. Both jets are Russian-made aircraft developed in the 1960s and 1970s and operated by the Syrian air force.

One day earlier, Israel launched two missiles from the David’s Sling missile defense system at two Syrian rockets which the IDF believed were heading for Israeli territory. When it became clear the two Syrian SS-22 missiles were going to land inside Syria, the David’s Sling missiles were ordered to self-destruct, the Israeli military said. One missile successfully self-destructed, while it was unclear what happened to the second, the military said.

It marked the first time David’s Sling has been used operationally. Designed to intercept medium and long-range missiles, David’s Sling is a larger, more powerful version of Iron Dome.

Israel last shot down a Syrian fighter jet in September 2014 under similar circumstances. The IDF said that jet – a Sukhoi 24 – had entered one kilometer into Israeli airspace before it was downed by a single Patriot missile. The pilot and co-pilot ejected and landed in Syria.

In February, Syria shot down an Israeli F-16 fighter jet which came under “massive anti-aircraft fire,” the IDF said at the time. The incident happened after an Iranian drone penetrated Israeli airspace, prompting Israeli airstrikes against Syria during which the fighter jet was downed.

Both pilots aboard the Israeli jet ejected. One pilot was severely injured during the ejection, while the second was lightly wounded.

As the Syrian regime has regained control of southern Syria, the border between Syria and the Israeli-occupied Golan Heights has seen increased activity. 

Thousands of Syrians, fleeing the fighting, established tent camps along the border. While Israeli soldiers turned away dozens of Syrians seeking refuge on the Israeli side of the fence, the army has been distributing food, clothing and supplies to Syrians hit by the fighting, in a program called Operation Good Neighbor.

Over the weekend, Israel assisted in the evacuation of hundreds of Syrian civilians, including members of the White Helmets volunteer rescue organization. An international effort, including the United States and Canada, backed the evacuation attempt, which saw the civilians transferred through Israel to Jordan.

While the operation was lauded by the international community, including the British Foreign Secretary who called it “fantastic news,” the Syrian government slammed the effort as a “criminal operation.”