Manila, Feb. 7 -- The United States military-contracted plane was providing intelligence, surveillance, and reconnaissance support at the request of the Philippine government when it crashed in Maguindanao del Sur, killing all four personnel on board.

"We can confirm no survivors of the crash. There were four personnel on board, including one US military service member and three defense contractors," the US Indo-Pacific Command (INDOPACOM) said Friday.

The plane, it said, was conducting a "routine mission in support of US-Philippine security cooperation activities" when it nose-dived into an open field in Barangay Malatimon on Thursday afternoon.

READ: 4 killed as private plane crashes in Maguindanao Sur

The US INDOPACOM said a probe ...