Soldiers gather around a part of a crashed helicopter retrieved from a pond in Prey Sar village in Cambodia. Pic: AP.

PHNOM PENH, Cambodia (AP) — Police in Cambodia say a military helicopter has crashed, killing five people on board.

It was not immediately clear what caused the accident.

A senior police officer at the international airport in the capital said Monday that the helicopter was on a training mission and went down about 10 kilometers (six miles) south of Phnom Penh.

The officer spoke on condition of anonymity because he was not authorized to speak to the media about the fatalities.

He said at least one person on board survived the crash but was seriously injured.