Updated

A South Korean military helicopter has crashed in an eastern province, killing three of the four soldiers on board.

Defense and army officials say the helicopter went down in a farming field in Chuncheon, about 85 kilometers (50 miles) northeast of Seoul, during a checkout flight on Monday.

The officials say that all four soldiers aboard the helicopter were initially rescued after the crash, but that three of them died while being treated in hospitals.

They say no casualties on the ground have been reported. The cause of the crash is under investigation.

The officials spoke on condition of anonymity, citing department rules.

South Korea maintains more than 600,000 troops to help deter aggression from rival North Korea.