New Delhi, March 13 -- Four of the six crew members aboard a US military KC-135 refueling aircraft that crashed in western Iraq have been found dead, the American military said.

"Four of six crew members on board the aircraft have been confirmed deceased as rescue efforts continue," US Central Command said in a statement.

"The circumstances of the incident are under investigation. However, the loss of the aircraft was not due to hostile fire or friendly fire," it added.

Though the details of those killed have not been revealed, according to The Associated Press, a basic KC-135 crew has three people: a pilot, a co-pilot, and a boom operator. Nurses and medical technicians are added to aeromedical evacuation missions.

The US military re...