Manila (Philippines), Feb 7 : A small plane contracted by the US Defence Department crashed in the southern Philippines on Thursday, killing all four people on board, including one US service member, the US Indo-Pacific Command said.

The crash occurred in Maguindanao del Sur in the southern Philippines. Images from the crash site, confirmed by a US Defence official, show the wreckage of a Beechcraft King Air 350 in a rice field.

The official said the service member killed in the crash was a US Marine. It is unclear if the three Defence contractors were also US citizens.

The twin-engine turboprop aircraft was contracted by the Defence Department to conduct intelligence, surveillance, and reconnaissance at the request of the Philippines, Indo-Pacific Command said.

The crash occurred during a "routine mission," and the cause of the crash is under investigation.

The aircraft is registered to Metrea Special Aerospace ISR, Inc., according to publicly available data.

Metrea's website shows a Beechcraft King Air 350 ' the type of aircraft that crashed ' and advertises "integrated, turnkey Airborne Intelligence, Surveillance, and Reconnaissance (AISR) solutions to our defence partners".

The crash comes one day after new Defense Secretary Pete Hegseth held his first call with his counterpart from the Philippines, Secretary of National Defense Gilberto Teodoro, Jr.

According to a readout of the call, the two discussed the importance of deterrence in the South China Sea and enhancing the capabilities of the Philippine military.

"The aircraft was providing intelligence, surveillance, and reconnaissance support at the request of our Philippine allies," the Indo-Pacific Command said in a statement about the crash on Mindanao island.

"The incident occurred during a routine mission in support of US-Philippine security cooperation activities."

The US military said one service member and three defence contractors were killed in the incident. They were not immediately identified pending notification of their families.

"We can confirm no survivors of the crash," the statement said.

Small numbers of American troops are put on short-term rotational deployments in the Philippines, where the US military has helped provide intelligence to troops battling militants linked to the Islamic State group that remains active on Mindanao.

The Philippine military said in a statement it could not release information about the crash as the matter was classified and an investigation was ongoing.

Police and soldiers were deployed to the site to prevent potential tampering with evidence, a police spokesman said.

/IANS