A coalition helicopter crashed in an area of southeastern Afghanistan early Sunday morning after reporting an engine failure, causing unknown casualties, a coalition statement said.

"A search and rescue operation for the helicopter and occupants is ongoing, and an investigation will be conducted into the cause of the incident,"the statement said.

During a telephone interview with Xinhua, a coalition spokesman David Accetta declined to say which province the crash occurred as "several military operations were going on there."

He also refused to tell the casualties in the crash and how many occupants the helicopter had carried "for the safety of the soldiers."

He only said "There is no indication that there was hostile fire in the area where the helicopter crashed."

Further information will be released as it becomes available, the statement said.

Source: Xinhua