At least one unidentified gunman opened fire at the U.S. Navy Yard in Washington on Monday and was at large after killing “multiple” victims and wounding several more, officials said.

Police and FBI agents descended on the area in force as helicopters swarmed overhead, amid reports a shooter was armed with an assault rifle and was holed up at the complex.

“We believe there were multiple deaths,” a U.S. defence official, speaking on condition of anonymity, told AFP. The precise death toll remained unclear, the official said. A Washington DC police officer and another law enforcement officer had been shot while the gunman had allegedly barricaded himself in a room in a headquarters building, media reported.

The Washington Post and other media also reported there were two shooters involved, but authorities could not confirm the account.

At one point a police helicopter hovering over the complex lowered a man down by rope into the compound.

It was unclear how a man armed with an assault rifle could have penetrated the heavy security that surrounds the Navy Yard, which is located on the Anacostia River, not far from the Capitol building that houses the U.S. Congress.

One employee at the Navy Yard, Patrica Ward, said she had just paid for her breakfast at a cafeteria when shots rang out. “I was waiting for my friend to pay for when we heard the gun shot. It was three gun shots straight in a row” she told reporters.

The guard “told all of us to just run, to get away as fast as you can.” She added that employees did not have to pass through a metal detector when they entered the building.

Police blocked off intersections around the Navy Yard as military troops in uniform stood guard at street corners and patrol boats moved in near the site along the banks of the Anacostia River.

The U.S. Navy on its Twitter account said “several” people had been injured and cited unconfirmed reports of deaths, while police told local media that up to 10 people had been wounded. “Several people were injured and there are reports of fatalities in a shooting at the Washington Navy Yard,” the Navy said in a statement. “Emergency personnel are on scene and a ‘shelter in place’ order has been issued for Navy Yard personnel,” it said. Several schools in the area were on lockdown as a precaution, authorities said, and flights out of the nearby Reagan National Airport were delayed. The Navy said at least three shots were fired at 8.20 a.m. (1320 GMT) in the headquarters building of the Naval Sea Systems Command.

About 3,000 people work at the headquarters, which is responsible for building and buying US warships and combat systems, the navy said. The complex also has a residence which serves as the home of the four-star chief of the U.S. Navy, Admiral Jonathan Greenert.

The White House said President Barack Obama had “been briefed several times about the unfolding situation at the Washington Navy Yard by Assistant to the President for Homeland Security and Counterterrorism Lisa Monaco and Deputy Chief of Staff Alyssa Mastromonaco.”

Flights suspended

Defence Secretary Chuck Hagel and the U.S. military’s top officer, General Martin Dempsey, were also closely following the incident.

Flights from Reagan were suspended for 90 minutes, and the Federal Aviation Administration said it expected “residual delays as the airport returns to normal operations.” —AFP

  • At least three shots were fired at 8.20 a.m. (1320 GMT) in the headquarters building of the Naval Sea Systems Command: U.S. Navy

  • Several schools in the area were on lockdown as a precaution: Authorities