This picture taken on October 19, 2021 and released from North Korea's official Korean Central News Agency (KCNA) on October 20, 2021 shows test fire of a new type submarine-launched ballistic missile in an undisclosed location in North Korea. (Photo by various sources / AFP) / South Korea OUT / ---EDITORS NOTE--- RESTRICTED TO EDITORIAL USE - MANDATORY CREDIT "AFP PHOTO/KCNA VIA KNS" - NO MARKETING NO ADVERTISING CAMPAIGNS - DISTRIBUTED AS A SERVICE TO CLIENTS / THIS PICTURE WAS MADE AVAILABLE BY A THIRD PARTY. AFP CAN NOT INDEPENDENTLY VERIFY THE AUTHENTICITY, LOCATION, DATE AND CONTENT OF THIS IMAGE --- /  (Photo by STR/AFP via Getty Images)
Explained: How much damage can North Korea's weapons do?
02:28 - Source: CNN
Seoul, South Korea CNN  — 

North Korea fired two short-range ballistic missile into waters off the east coast of the Korean Peninsula on Friday, according to South Korean military officials, adding to tensions in the region.

The missiles were fired from Tongchon county in North Korea’s eastern Kangwon province between 11:59 a.m. and 12:18 p.m. local time and flew about 230 kilometers (143 miles) with an altitude of about 24 kilometers (15 miles), according to a statement by South Korea’s Joint Chiefs of Staff (JCS).

The test was a “serious act of provocation” that threatens peace and stability on the peninsula and a “clear violation” of United Nations Security Council resolutions that ban ballistic missile launches by North Korea, the JCS said, adding it was working with the United States to monitor North Korean movements.

The US military said it was aware of the North Korean launch, which “does not pose an immediate threat to US personnel or territory, or to our allies,” according to a statement from the US Indo-Pacific Command.

Friday’s launch is North Korea’s 28th this year, according to a CNN count, and comes as South Korea wraps up its Hoguk military drills – a joint amphibious operation between the South Korean navy, marine corps and air force.

Earlier this month, North Korean state media broke six months of silence over this year’s spate of missile tests, claiming they were meant to demonstrate Pyongyang’s readiness to fire tactical nuclear warheads at potential targets in the South.

The aggressive acceleration in weapons testing has sparked alarm in the region, with the US, South Korea and Japan responding with missile launches and joint military exercises.

Next week, South Korea is set to conduct a large-scale joint air force training with the US involving the US’ F-35B stealth jet, according to the South Korean Air Force.

Experts have previously told CNN that North Korean leader Kim Jong Un could be sending a message by deliberately showcasing the nation’s arsenal during a period of heightened global conflict.

South Korean and US officials have been warning since May that North Korea may be preparing for a seventh nuclear test – its first since 2017 – with satellite imagery showing activity at its underground nuclear test site.

Speaking to reporters on Thursday, the head of the UN’s nuclear watchdog said “everybody is holding its breath about” a potential North Korean nuclear test, which could provide further “confirmation of a program which is moving full steam ahead in a way that is incredibly concerning.”

“We are following this very, very closely. We hope it doesn’t happen but indications unfortunately go in another direction,” said IAEA Director-General Rafael Grossi.

CNN’s Yoonjung Seo and Mohammed Tawfeeq contributed reporting.