TAICHUNG, Taiwan (AP) — Taiwan's military fired missiles from the air and the island's shore facing China on Thursday in a live-fire drill to demonstrate its ability to defend against any Chinese invasion.

One helicopter crashed when returning to base from another drill, killing the pilot and co-pilot, the army said. The cause of the crash was under investigation. The drills were part of a five-day annual exercise that ends Friday.

Assault helicopters launched missiles and fighter jets dropped bombs on targets at sea, while tanks and missile trucks fired from a beach to deter a simulated invading force.

“We want the world to see our determination and efforts to protect our country.” President Tsai Ing-wen said, observing the exercise in a helmet and camouflage military fatigues.

China regards Taiwan as a breakaway province that is part of its territory. The self-governing island of 24 million people lies 160 kilometers (100 miles) off China's southeast coast across the Taiwan Strait.