A U.S. drone aircraft has crashed at an airport in the Seychelles.

The U.S. embassy in nearby Mauritius says the remote-controlled MQ-9 aircraft crashed Tuesday at the Seychelles International airport on the island of Mahe.

Officials from the Seychelles Civilian Aviation Authority said the drone was on a routine patrol and developed engine problems minutes into its flight.

The embassy did not comment on the plane's mission and said the cause of the crash was unknown.

No injuries were reported.

The U.S. military has operated a small fleet of drones out of the Seychelles since 2009 to monitor Somali militant group al-Shabab and other groups liked to al-Qaida.

Last week, Iran announced that it downed a U.S. drone in the eastern part of the country near the border with Afghanistan.