SEOUL, KOREA - AN army helicopter crashed in South Korea early on Wednesday, killing all seven people on board, army officials said, according to Yonhap news agency.

The chopper crashed around 1:40am (12.40am Singapore time) in Gyeonggi Province in the north of the country while returning to its base after dropping off an emergency patient at a military hospital near Seoul, Yonhap said.

The wreckage was located shortly before 4:00am, according to the officials. Investigators are still trying to verify the cause of the crash.

'Immediately after the accident, the army searched the area, mobilising all its available sources and located the bodies of all seven people on board and the wreckage of the helicopter,' the Army Public Affairs Office said in a statement reported by Yonhap.

On board the aircraft were two army pilots, two medical officers and three others, the statement said. -- AFP