Boston police say two officers have been shot and wounded and the suspect is dead.
Police say the officers were responding to a report of a person with a gun late Wednesday night (Thursday AEDT) in East Boston when they came under fire.
One of the officers was shot multiple times and is hospitalised in critical condition. The other officer is listed in stable condition.
Police initially asked residents in the East Boston neighbourhood to shelter in place as they searched for a suspect. They later said the suspect was killed and the situation was under control.
Boston Police Commissioner William Evans says the incident is "possibly a domestic incident gone bad."
"I commend the officers. They moved in and neutralised the threat pretty quick that no one else got killed," he said.
Police did not immediately identify the suspect or the wounded officers.
Evans said that he and Boston Mayor Martin Walsh were headed to the hospital to meet with the officers' families.
