Washington: Several online jihadists have claimed Islamic extremists were involved in the deadly shooting incident at the Naval Sea Systems Command office in Washington on Monday that killed a dozen people and left another dozen injured.
US officials have, meanwhile, ruled out the involvement of any terrorist group in the attack, the Washington Times reports.
Police said that an ex-military officer, who was killed in the gunfight, was behind the attack, but the motive had to be still be ascertained.
The FBI identified the dead gunman as Aaron Alexis, who is said to be suffering with Post-Traumatic Stress Disorder, and used to meditate regularly at a Buddhist temple in Texas.
The Navy Yard is located less than three miles from the White House, the report added.
The FBI is investigating the shooting with the possibility that it might have been carried out by what are termed as `homegrown violent extremists` (HVEs).
D.C. Police Chief Cathy Lanier said two other suspects wearing military uniforms were spotted on security surveillance video.
However, one of the two suspects was ruled out later on and police continued a manhunt for the second suspect.
Police have warned the residents and businesses in the area of the shooting to move in shelter.
The Nationals game scheduled for Monday night was postponed until Tuesday, the report added.