A Baltimore police officer is in Shock Trauma and a suspect and another man were killed Monday morning after a shooting at a local methadone clinic.

Baltimore Police Commissioner Michael Harrison said the shooting was reported at 7:09 a.m. at the Man Alive methadone clinic on Maryland Avenue. Police received a call for an armed person, WBAL TV reports.

"When [officers] arrived, this was actually treated as an active shooter scenario because we were informed when we got there (that) there was a suspect in the building who had fired a gun at least two times," Harrison said.

Harrison said the officers tried to de-escalate the situation, but the suspect began shooting at the officers.

Baltimore police Sgt. Bill Shiflett, a 25-year veteran assigned to the Northern District, was shot in his lower abdomen under his bulletproof vest. Shock Trauma officials said Shiflett underwent surgery and was taken to the intensive care unit. He is reportedly stable and in the intensive care unit.