WASHINGTON - One suspect was pronounced dead in Washington Navy Yard on Monday morning, and the police were searching for two other potential shooters at large, said local police authorities.

One suspected shooter was killed on site, and the police believed there are two other potential shooters on the loose, said Cathy Lanier, chief of Washington Metropolitan Police Department, in a briefing.

She said one police officer was shot in engagement with the suspects of the shooting.

The incident happened at 8:20 am EDT (1320 GMT) when at least a shooter opened fires inside a building at the Washington Navy Yard that serves as the headquarters of the Naval Sea System Command Headquarters, the US Navy said on Twitter.

Authorities were yet to confirm the number of casualties. But Pentagon press secretary George Little said there were believed to be "loss of life and several injuries."