South Korea’s military scrambled stealth jets on Friday after detecting the mobilisation of 180 North Korean warplanes, Seoul said, following a record-breaking blitz of missile tests by Pyongyang this week.

It comes a day after North Korea conducted a failed intercontinental ballistic missile test and follows a decision by Seoul and Washington to extend through Saturday their largest-ever joint air drills, a military exercise that has infuriated Pyongyang.

“Our military detected around 180 North Korean warplanes” mobilised in Pyongyang’s airspace, Seoul’s Joint Chiefs of Staff said...