(CNN) -- Syrian rebels and an al-Qaeda-affiliated group have captured a government air base near the key city of Aleppo, an opposition group said.
"Early dawn today, the Islamic State in Iraq and Syria and some rebel battalions took full control of the Menagh air base," the London-based Syrian Observatory for Human Rights (SOHR) said Tuesday.
"The start of this new offensive started yesterday when two non-Syrian nationals blew themselves up in an armored vehicle in front of the command center of the Menagh air base," the group added. The SOHR said one suicide bomber was a Saudi Arabian.
Fighters from the Islamic State of Iraq and Syria and various rebel battalions destroyed several tanks and killed a number of regime soldiers, the observatory said. At least 10 rebel fighters, including foreigners, were also killed, the group added
The Islamic State of Iraq is the rebranded name for al Qaeda in Iraq. The group changed its name after its founder, Abu Musab al-Zarqawi, was killed by a U.S. missile strike in 2006.
The expanded term "Islamic State of Iraq and Syria" was spawned when the ISI moved into Syria. However, al Nusra Front -- a group inspired by al Qaeda that has fought alongside rebels in Syria -- has denied the existence of a merged group.
The Menagh air base is north of Aleppo, Syria's largest city and financial hub. For many months, rebels have tried to wrest control of the city in their attempt to topple four decades of rule by President Bashar al-Assad's family.
The Syrian regime downplayed reports that opposition fighters -- whom it calls "terrorists" -- had taken over Menagh air base.
"The heroes of our armed forces are confronting the terrorists with matchless valor," the state-run Syrian Arab News Agency reported. SANA said the airport is devoid of military equipment and aircraft and is not in service.
Elsewhere, a car bomb exploded in Jarmana in southern Syria, killing 18 people, including three children, and wounding dozens more, the state-run Syrian Arab News Agency (SANA) reported Tuesday.
CNN cannot independently confirm casualty tolls as the Syrian government has severely restricted the access of international journalists.
CNN's Mohammed Tawfeeq, Nic Robertson and Paul Cruickshank contributed to this report.