An off-duty D.C. police officer was shot and killed Monday night in a domestic dispute at a house in Prince George’s County, the county police said.

The male officer, who was killed in a gated community in the Upper Marlboro area, was not immediately identified. He was shot by someone believed to be a family member, said Cpl. Maria McKinney, a spokeswoman for the county police.

No arrest was reported late Monday night, but police surrounded the house where the shooting apparently occurred. Police tweeted at about 3 a.m. Tuesday that a barricade erected near the home was being removed. The tweet said police believed the “domestic murder suspect is out of the immediate area. Active search underway.”

No specific motive for the shooting could be learned, and no information was available about the gun involved.

McKinney said police were called about 8:10 p.m. to the 6700 block of Green Moss Drive, where a shooting was reported.

The street is within the Avalon community. A resident said he heard several shots about 8 p.m.

Police arrived and began searching, the resident said. The development is made up of large, well-spaced houses with ample lawns.

“It’s a very nice community,” the resident said, “so this is odd.”