‘Active shooter’ at Washington Navy Yard on the loose; at least 10 people shot, including two police officer: Navy

Several others, including officers, may have been injured in the shooting. Authorities are on the scene inside a military building. Gunman is still on the loose.

 Police respond to the report of a shooting at the Navy Yard in Washington, DC, September 16, 2013. A gunman shot and wounded at least one person Monday in a headquarters building at the US Navy Yard in Washington and is still at large, the navy said."There is one confirmed injury. Emergency personnel are on scene and a 'shelter in place' order has been issued for Navy Yard personnel," the navy said in a statement. Local television reported that there were as many as five casualties and the Navy said that police had entered building number 197 in search of the shooter. The Navy said at least three shots were fired at 8:20 am (1320 GMT) in the headquarters building of the Naval Sea Systems Command. AFP PHOTO / Saul LOEBSAUL LOEB/AFP/Getty Images

The U.S. Navy says one person is injured after a shooting at a Navy building in Washington, but local reports indicate there may be more victims.    SAUL LOEB/AFP/Getty Images

SOURCE – Several people were reportedly killed and more were wounded Monday at the Washington Navy Yard when three fatigue-clad gunmen armed with assault rifles barged inside and opened fire.

Police swarmed the Navy Yard in Washington, D.C. on Monday after gunfire sent people running from building number 197 at 8:20 a.m.

Police swarmed the Navy Yard in Washington, D.C. on Monday after gunfire sent people running from building number 197 at 8:20 a.m.     SAUL LOEB/AFP/Getty Images

One of the intruders was reported “down,” but it wasn’t clear if the gunman was wounded or killed. Police were believed to be closing in on the others.

Two police officers were among the wounded, including a Washington D.C. cop who was hit twice in the legs, according to local media.

A police helicopter flies overhead as police walk on the roof of a building.

A police helicopter flies overhead as police walk on the roof of a building.   JOSHUA ROBERTS/REUTERS

The eight other victims were reportedly all civilians who work at the base in southeat Washington.

It was not immediately clear who the gunmen were, but everybody from SWAT teams to the Marines were on the scene and overhead a half-dozen choppers were circling the base.

Authorities are looking for a black male wearing a black t-shirt and a black hat, according to police.

Authorities are looking for a black male wearing a black t-shirt and a black hat, according to police.                                  SAUL LOEB/AFP/Getty Images

President Obama was briefed on the unfolding drama by homeland security adviser Lisa Monaco.

The shooting erupted around 8:20 a.m. at the Naval Sea Systems Command Headquarters building were about 3,000 people work, polie said.

Frightened witnesses were escorted from the building after shots were fired early Monday morning. "@LahdeePops" was one of several people who said they were inside.

Frightened witnesses were escorted from the building after shots were fired early Monday morning. “@LahdeePops” was one of several people who said they were inside.   @LahdeePops via Twitter

Sirens immediately began wailing as officials sounded the alarm and the entire base went into crisis mode.

Police immediately shut down the 11th Street bridge to cut off a possible escape route and were heading to the nearby metro station to close that off as well.

The nearly Tyler Elementary School was on lockdown.

But flights in and out of nearby Reagan National Airport resumed at 10:30 a.m.

The base is also headquarters for the Naval Historical Center and numerous naval commands.