A man was shot and killed Tuesday night at a Metro station in the Temple Hills area of Prince George’s County, authorities said.

The shooting occurred about 9:30 p.m. in a bus bay at the Southern Avenue station on the Metro’s Green Line. The station is just across the street from the District.

The victim, who appeared to be about 40 years old, was not identified. He was apparently shot at least once in the head. There was no indication of any motive in the shooting or of any incident that led to it.

Metro officials said that after the shooting it was believed that a suspect ran into the station’s above-ground mezzanine, entering one side of the structure and running out the other.

Metro spokesman Dan Stessel said the suspect was described as a black man in his late 20s, about 5 feet 8 and 220 pounds, with a full beard. He wore a black hoodie and blue jeans, Stessel said.

The station sits parallel to Southern Avenue, and the shooting occurred between the avenue and the station, Stessel said.

The station was closed to passengers. Trains ran through it but did not stop. Bus shuttle service was set up.

Stessel said he expected full service to be restored by Wednesday morning’s rush hour.

Homicides on or near Metro property are rare.

Bus bays are used by buses taking people to and from the station. It was not known Tuesday night whether the victim or the suspect had arrived at the station by bus, or whether one or both had been waiting for one.

Stessel said Prince George’s County police would take the lead in the investigation.