Japan scrambled fighter jets in response, with the helicopters returning to their frigates without violating Japanese airspace

Ten Chinese and Russian warships sailed Monday through the Tsugaru Strait, a narrow chokepoint between Japan's main island of Honshu and the northern island of Hokkaido. Tsugaru Strait, between Honshu and Hokkaido, includes international waters. They were apparently part of a joint exercise in the Sea of Japan