South Korea scrambled around 80 fighter jets after about 180 radar tracks of North Korean warplanes near the countries' eastern and western maritime borders were detected, South Korea's military said Friday, in the latest sign of escalating tensions following successive missile launches by Pyongyang in recent days.

South Korea's Joint Chiefs of Staff said that fighter jets including F-35As and other military aircraft were scrambled after North Korean planes were detected from around 11 a.m. to 3 p.m.

U.S. and South Korean fighter jets fly over waters off South Korea's western coast on June 7, 2022. (Photo courtesy of South Korea's Defense Ministry)(Kyodo)

The United States and South Korea are in the midst of a joint air exercise involving 240 warplanes.

Pyongyang has strongly protested about the Vigilant Storm air exercise, firing a barrage of ballistic missiles on Wednesday and Thursday.

The joint exercise was originally planned to run from Monday to Friday, but it was extended given the heightened tensions on the Korean Peninsula following the North Korean missile launches. It was extended by one day, according to South Korea's Yonhap News Agency.