One person was killed and four others were injured after a gunman opened fire Thursday morning in Washington, D.C., the BBC reported.

The shooting began inside a gym in an apartment building in the Logan Circle neighborhood, about a mile (1.6 kilometers) north of the White House. Police later identified the gym as Vida Fitness, according to a witness account the BBC relayed from the Washington Sun. Of those injured, one was in critical condition and the others had non-life-threatening injuries, the BBC said. Authorities were still working to establish the exact timeline, the suspect's motivation and other details. The BBC report did not name the person who was killed.

Jefferey Carroll, the interim chief of the Metropolitan Police Department, said at a news conference that the male suspect was "contained" after barricading himself in one of the apartments and later confirmed that he had died. While barricaded, "he did fire through the door at officers at least on two occasions," Carroll said. Negotiators had been on the phone with the suspect when they heard a gunshot and he stopped communicating. Officers forced their way in and saw what appeared to be a "self-inflicted gunshot wound," Carroll said. He also said police "believe there was a fire that was set," which has been contained.

"We believe there was some sort of a conflict with the apartment building, but we don't have much more than that," Carroll said. Mayor Muriel Bowser called it a "senseless act of gun violence" and said the White House had been briefed.

What people inside the building described

Jonathan Csapo, a BBC producer who lives in the building, said a fire alarm went off. As he came out of a fire escape, he heard gunshots very close by. "I could see the smoke, I could see the flash. We just all started running. That was our first instinct," he said. He took cover behind a brick structure near the building, then was taken to a safe room by a building manager. "And then everybody started screaming," he said.

Michael Carney told the Washington Sun he was on a treadmill at the Vida Fitness gym when the shooting started. He heard "one pop" that he assumed was an exercise ball bursting, then saw a victim on the floor who had been shot. "Everyone was kind of just hiding behind planters and stuff," he said, and a fire alarm was pulled. Once outside, he heard five or 10 shots that seemed to be coming from a nearby alley. Another witness told the Washington Sun she heard "an enormous, loud thing" in the fitness center and more shots outside after being evacuated. "I thought something had crashed or fallen," she said. "I didn't know it was a gunshot until later."

Police had not, in the BBC account, announced charges or a completed investigation. Carroll's description of a possible conflict with the apartment building was preliminary.