Police are investigating a shootout on the border of Montgomery County and the District between police and an armed man March 9, authorities said.

Montgomery County police responded to the 8100 block of Eastern Avenue shortly after 12:30 a.m when multiple callers reported hearing gunshots fired. Officers found an armed man on the north side of Eastern Avenue inside the District, who then exchanged shots with the police. The number of shots fired and the nature of the shooting itself is currently unknown, authorities said.

Police said one officer was injured in the gunfight and was taken to a hospital. The officer was treated and later released. The suspect is in critical condition at MedStar Washington Hospital, police said.

D.C. police are investigating the shooting while the Montgomery County police are conducting the internal investigation of its officers. Police said the identities of the suspect and involved officers will be released at a later time.