A U.S. service member and three defense contractors were killed after a military-contracted plane crashed in the Philippines on Thursday, authorities said.

The crash happened around 2 p.m. local time, in Ampatuan, a municipality in the southern province of Maguindanao del Surf, the Xinhua News Agency reported.

The plane, which was contracted by the U.S. Department of Defense, crashed in a rice field about half a mile from a cluster of farmhouses, according to Windy Beaty, a provincial disaster mitigation officer.

There were no reported injuries on the ground, though a water buffalo was said to have been killed in the crash.

The plane was a Beech King Air 350, a twin-engine turboprop aircraft that’s typically outfitted with two cabin zones and has a range of 1,440 nautical miles (approximately 1,600 miles), the Philippine News Agency said.

It had been “providing intelligence, surveillance, and reconnaissance support at the request of our Philippine allies,” according to the U.S. Indo-Pacific Command, the unified combatant command of the U.S. Armed Forces responsible for the Indo-Pacific region.

The incident occurred “during a routine mission in support of U.S.-Philippine security cooperation activities,” the agency said in a statement Thursday, adding that the cause of the crash remains under investigation.

The victims’ identities are being withheld until their next of kin have been notified.

Last week, a Philippine national died in the collision between an American Airlines jet and a U.S. Army Helicopter near Washington, D.C. that killed all 67 people onboard both aircraft.

Pergentino Malabed Jr., a Philippine National Police officer, was “fulfilling his duty as a dedicated police officer” at the time of the crash, the Philippine Embassy confirmed.

“His untimely passing is a profound loss to the PNP, where he served with honor, integrity and dedication throughout his career,” the PNP said in a statement.

With News Wire Services