A U.S. reconnaissance plane returning to Africa after a mission in Afghanistan crashed, killing four Air Force personnel, including a senior airman from Upper Marlboro, the Pentagon announced.

The Pentagon said the cause of the accident is under investigation.

Amy Oliver, public affairs director of the Air Force 1st Special Operations Wing, told the Associated Press that the U-28 plane was returning from a mission in support of the Afghanistan war when the accident occurred.

Julian S. Scholten, 26, was among those killed in the crash Saturday night near Camp Lemonnier in Djibouti.

The U.S. Africa Command said the airmen were on a “routine” flight and that the crash occurred six miles from Djibouti International Airport.

Scholten was assigned to the 25th Intelligence Squadron at Hurlburt Field, Fla. The Defense Department described Scholten and the others as supporting Operation Enduring Freedom, the military’s broad anti-terrorism operation that includes significant operations in Africa. Efforts to reach his family on Monday were unsuccessful.

According to a news release from Hurlburt Field, Scholten was a mission systems operator who had been assigned to the base since 2009. He enlisted in the Air Force in 2007.

In December, Defense Secretary Leon Panetta visited Camp Lemonnier, which is near the Somali border, and called Djibouti “a central location for continuing the effort against terrorism.”

Also killed in the crash on Saturday were Capt. Ryan P. Hall of Colorado Springs; Capt. Nicholas S. Whitlock of Newnan, Ga.; and 1st Lt. Justin J. Wilkens of Bend, Ore.