16 August 2012 Last updated at 10:54 ET

Security guard shot at Family Research Council

Police say it is too early to tell exactly what led to the shooting

A security guard is recovering after being shot at the headquarters of a conservative Christian lobby group in Washington DC.

Police say a man was restrained and disarmed after opening fire in the lobby of the Family Research Council at 10:45 local time (14:45 GMT).

The guard was admitted to hospital with a gunshot wound to the arm and is in stable condition, police said.

The Family Research Council opposes gay marriage and abortion.

An FBI spokeswoman said there had been an altercation between the suspect and guard before the shooting, although it is not clear what caused the attack.

"We don't know enough yet about him... or mentally what he's thinking," said James McJunkin, assistant director of the FBI's Washington DC field office.

One law enforcement official said the suspect had made a negative remark about the organisation's work, before opening fire on the guard, the Associated Press reported.

A visitor to Washington was asking a police officer for help with a parking meter outside the building as the situation unfolded.

As the office door opened an officer repeatedly shouted "Put the gun down, put the gun down," Amy Biondi said. "Next thing you know there are police officers swarming the area."