At least 13 people are confirmed dead after a mass shooting at a US Navy base in Washington DC.
As hundreds of staff were evacuated from the complex, police searched inside, believing at least one gunman to be at large.
Earlier they said that three individuals wearing military-style uniforms had opened fire at breakfast time.
One of the gunmen was shot dead, they said, adding that they were looking for two more. But one suspect is now said to have been discounted and there is confusion over how many have been involved.
Several people were wounded and were taken to hospital. At least one was evacuated by helicopter. The victims included police officers and civilians.
Washington Navy Yard houses one of the main naval centres in the US. It is where ships, submarines and combat systems are built and maintained.
It lies in a populated area in the southwest of the city. In the surrounding area streets were closed off; schools locked down. Flights were suspended for a while at Washington’s Reagan national airport.
Staff inside the base were told to seek shelter and stay put.
The motive for this attack is unknown. The FBI is investigating.
President Barack Obama called it “yet another mass shooting” in the US and vowed that whoever carried it out would be held responsible.