Police say as many as two gunmen may still be at large near the D.C. Navy Yard Monday after a shooting that began in a heavily secured building and left a number of people dead.
One other gunman has been killed, Metropolitan Police Chief Cathy Lanier said at a midday press conference.
Initial reports had said that 11 people were shot on base and four had died, but Lanier said that information was preliminary. "There are multiple victims inside deceased," Lanier said.
They are seeking two other people as "possible" gunmen, Lanier said. One was a white male, wearing a khaki military-type uniform and a beret hat. He was armed with a handgun, and was last seen about 8:30 a.m., Lanier said.
Lanier also said police were seeking a black man, aged about 50, who was wearing olive drab and was armed with a "long gun," though she did not give any other details about the weapon.
President Obama mentioned the shooting in remarks from the White House Monday. "We do know that several people have been shot and some have been killed," he said. "We are facing another mass shooting."
Though Lanier stressed that the scene was contined, people near the base are being asked to stay in their homes, and eight D.C. public schools and one private school nearby have been locked down.
A large search, including from helicopters, continues. "It's a large piece of land with many buildings," Assistant D.C. Police Chief Peter Newsham told News4. "It's going to take a while to determine that it is safe."
Tactical teams have entered at least two buildings on the Navy Base to search for the shooter, and News4's Mark Segraves reported that three helicopters were seen tightly circling part of the base earlier.
Earlier Monday morning, the one known gunman walked into Building #197 at the Naval Sea Systems Command Headquarters, 1336 Isaac Hull Ave. in the Southeast section of the District. He shot a security guard in the head, killing him, sources confirmed to News4's Jackie Bensen.
The gunman then walked through the building, and seemed to target victims, Bensen reported. Some reports indicate he was armed with an AR-15, a military-style assault weapon.
D.C.'s Metropolitan Police Department and several other law enforcement agencies responded, Bensen said. During that response, a MPD officer was shot in the leg.
That gunman was then shot by a FBI hostage response team, Bensen said.
MedStar Washington Hospital Center said the MPD officer was among three victims that had been transported to that hospital. The officer was shot in the legs; one other victim was shot in the shoulder and one was shot in the head and hand.
All are alert and speaking at this time, and there is a "very good chance they will survive," said Dr. Janis Orlowski, chief medical officer at the hospital.
However, the hospital has been prepared to expect more victims.
George Washington University Hospital said they had also received a victim, a man in his 60s who had been shot in the temple. Despite efforts at CPR, he was prounounced dead at the hospital.
One victim was evacuated from the roof of a building, reported News4's Tony Tull. A U.S. Park Police helicopter hovering above the scene around 9:50 a.m. lowered a basket to a building and lifted what appeared to be a shooting victim from the roof. The helicopter came back to the scene just after 10 a.m. to retrieve another victim.
But other details were sketchy from the scene, which continued to evolve through the morning. Shots rang out several times, including a volley that Tull reported at about 9:20 a.m. and another volley that News4's Mark Segraves heard at about 11 a.m.
Federal and local emergency personnel converged on the scene, and a shelter in place order has been issued for Navy Yard personnel, the Navy said.
Obama continues to get frequent briefings about the deadly shooting from senior aides. The White House says Obama directed his team to stay in touch with the Navy, FBI and local officials as the events unfold.
The Navy Yard is located in southeast Washington on the Anacostia River. The Navy says 3,000 people work inside the building, including command staff, headquarters directorates and field activities. They coordinate the Naval Sea Systems Command, or NAVSEA, the largest of the Navy's five system commands.
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Copyright Associated Press / NBC4 Washington