Taiwan's navy has held a major live-firing exercise off the island's east coast in an area increasingly threatened by Chinese ships and planes.
Wednesday's drills are part of the annual Han Kuang exercises that simulate an attack by China, which claims Taiwan as its own territory to be annexed by force if necessary.
In addition to firing of cannons and missiles by navy craft and the release of depth charges, fighter jets launched missiles and anti-submarine warfare aircraft released buoys, reports the Associated Press.
Along with its vast array of ballistic missiles, submarines are considered among China's most potent weapons against Taiwan, which split from the mainland amid civil war in 1949.
China has upped its military threat against Taiwan, with President Xi Jinping this year saying Beijing would not rule out using force.