UPDATE*****A dead gunman, Aaron Alexis, 34, originally of Fort Worth, Texas, who recently began working as a civilian contractor has been identified as one of the shooters.
VOA News is carrying a live Blog on the ongoing events surrounding the shooting at the Washington Navy Yard.
Emergency vehicles and law enforcement personnel respond to a shooting at an entrance to the Washington Navy Yard, Sept. 16, 2013.
Police respond to the shooting at the Washington Navy Yard, Sept. 16, 2013.
A police helicopter is seen as police walk on the roof of a building as they respond to a shooting at the Washington Navy Yard, in Washington, Sept. 16, 2013.
A police helicopter lifts what appears to be a shooting victim up as it hovers over a rooftop on the Washington Navy Yard, Sept. 16, 2013.
A helicopter pulls what appears to be a shooting victim up as it hovers over a rooftop on the Washington Navy Yard, Sept. 16, 2013.
A helicopter lifts a person off the roof as police respond to the report of a shooting at the Navy Yard in Washington, Sept. 16, 2013.
A police helicopter flies overhead as police walk on the roof of a building as they respond to a shooting at the Washington Navy Yard, Sept. 16, 2013.
Police work the scene near the Washington Navy Yard, Sept. 16, 2013.
A police vehicle is seen as police respond to a shooting at the Washington Navy Yard, Sept. 16, 2013.
Police work the scene after a gunman was reported at the Washington Navy Yard in Washington, Sept. 16, 2013.
Members of the United States Marine Corps maintain a watch on their barracks as police respond to a shooting at the Washington Navy Yard, Sept. 16, 2013.
2:20 pm Shooting appears over, but people still missing
2:07 pm Congress recesses for day because of shooting
2 pm DC Police Chief Cathy Lanier and Mayor Vincent Gray hold second press conference of day:
Mayor Gray: At this hour, it appears we have at least 12 fatalities. We're continuing to try to determine how serious situation is. It doesn't get much more serious than that.
One police officer is injured.
There is no known motive at this stage. We don't have any reason to think it's a terrorist event. Continuing investigation.
Police Chief Lanier: Actions by police officers reduced lives lost. Our gratitude to frontline officers and also to U.S. Park Police, who ran into danger.
We're confirming at least 12 fatalities.
We had a few additional folks injured, not fatally. We have additional officers injured, only one by gunfire. Other injuries sustained by multiple police agencies on the large response inside.
Offficially now transitioning to FBI lead. FBI will lead entire investigation as unified process.
Any additional information anyone wants to share can be called in to: 1-800-Call-FBI.
Other suspects are white male, between 40 and 50 years of age, wearing what appears to be a tan military uniform and a beret-syle hat. Looking also for a black male, between 40 and 50 years old, in an olive military-style uniform. Approximately 5 foot 10 inches, 180 pounds, medium complexion with graying sideburns.
No indication of any motive.
We are updating and asking family members to call NCIS at 202.433.6151 or 202.433.9713.
Impact of area - large part of area is in lockdown. Asking residents to stay in their homes and stay out of the area.
There are multiple agencies on the scene. Lots of support from regional counterparts.
There are few questions we can answer at this point. Another update will come in two hours.
Multiple pieces of information at least two other individuals were seen with firearms, wearing military-style uniforms.
1:54 pm Authorities are still clearing Navy Yard buildings:
1:33 pm DC Fire Department calls many units home
1:13 pm DC school officials raise number of schools on lockdown from six to eight as authorities search for two suspected shooters.
12:32 pm U.S. President Barack Obama addresses press:
I've been briefed by my team. We still don't know all the facts but we do know that several people have been shot and some have been killed.
It's a shooting that targeted military and cilvilian personnel. These were men and women going to work, doing their job. They were protecting all of us. They were patriots and they know the dangers of serving abroad ... but today they faced the unimaginable violence that they wouldn't have expected here at home.
I want the investigation to be seamless so that federal and local authorities are working together and as this investigation moves forward we will do everything we can to make sure whoever carried out this cowardly act is held responsible.
We stand with the families of those who have been harmed. They're going to need our love and support.
12:16 pm DC Police Chief Cathy Lanier and Mayor Vincent Gray press conference:
BREAKING: One shooter dead. Authorities are searching for two other suspected shooters. Suspects are believed to be wearing military-style uniforms but Chief Lanier says there is no reason to believe they are military personnel.
Police Chief Cathy Lanier: Still very preliminary. Still a lot of work to be done. Will be doing another briefing in next two hours.
Initial call for shooting came in shortly after 8:15 am. Units on the scene within 7 minutes of first call coming in. Multiple shooter teams from Park Police, U.S. Marshalls, FBI and DC police.
One MPD officer shot in engagement with the shooter. One shooter believed involved with this is deceased. Other casualties. Multiple victims inside that are deceased. Will update once numbers are confirmed.
Potentially have two other shooters that we have not located. Not confirmed, but one shooter is a white male last seen around 8:35 am in a khaki, tan military uniform, short-sleeve with a beret hat, appeared like a Navy uniform. Last seen with a handgun.
Looking for another black male, approximately 50 years of age, who may have been in posession of long gun. Wearing olive drab, possible military-style uniform.
No reason to believe the suspects are military personnel but we do believe they are wearing military-style uniforms.
Tips can be called in to 202.727.9099
DC Mayor Vincent Gray: A shooter entered building 197, which is a naval sea command and began shooting. Police department active shooter team responded immediately, launched search for shooter and engaged at least one person along the way.
We know four wounded, removed from scene. Still trying to confirm number of fatalities involved. Will do that later.
As far as we know, this is an isolated incident. We don't know of any other instillations involved. We ask all residents to stay out of area. This is an active investigation. Because this involves the military and the federal government, we are actively and directly in contact with the White House.
11:51 am One gunman is dead, according to CNN, NBC, and the Associated Press. More information is expected momentarily, as DC police chief addresses press.
11:50 am U.S. Navy say emergency personnel remain on the scene and shelter in place order is still in place. NCIS, FBI and DC police are on the scene.
11:49 am Police spokeswoman says there was no shooting at Bolling Air Force Base, as reported by some new outlets. She says DC mayor and police chief expected to address the press in about 20 minutes
11:48 am U.S. Navy sets up emergency information phone lines
11:35 am Press conference with Janis Orlowski, chief medical officer, Washington Hospital Center:
Hospital received three gunshot victims, all in critical condition. Patients include one male DC police officer and two female civilians.
We understand there are individuals at the scene who will not be transported because they are deceased.
Orlowski says "let's pray for individuals at the Navy Yard" and promises to return with more updates.
11:33 am Secretary of Navy Ray Mabus:
I have complete confidence in our first responders, and I continue to be completely focused on this very difficult situation.
11:30 am Neighborhood watch:
11:20 am Police update casualties, saying 12 people shot, at least four killed. Of the wounded, six are civilians, two are police offficers. Pentagon so far confirming only one dead.
11:07 am Police say family members separated by crisis may reunite at National Stadium Parking Lot B.
11:00 am DC police expected to address press in next 15 minutes.
10:55 am Police lockdown six D.C. public schools and one administrative building as a precaution. Authorities are urging people in the area to stay inside.
10:40 am Authorities lift ground stop at Reagan National Airport. Flight operations return to normal at Reagan National after more than two dozens flights were put on temporary hold by the Federal Aviation Administration.
10:26 am Nearly two hours after first reports of shooting emerged, the area is still on lockdown
The U.S. Navy says several people have been wounded in a shooting at the Washington Navy Yard.
A person with a gun was reported inside the Naval Sea Systems Command Headquarters building early Monday. Via Twitter, the Navy confirmed "several injuries with reports of fatalities." News reports say one of the wounded is a police officer.
Security personnel were searching for the shooter.
The White House announced that President Obama has been briefed on the situation.
The Washington Navy Yard is located about two kilometers from the U.S. Capitol.
The Naval Sea Systems Command's headquarters is the work place for about 3,000 people. The Command is in charge of engineering, building, buying and maintaining ships, submarines and combat systems.
8:34 am Witness reports begin emerging
just heard a lot of sirens go by, heading to the #navyyard RT @IAFF36 Confirmed active shooter on grounds of Navy Yard with multiple victims8:15 am DC police receive call about shooting at Washington Navy Yard