WASHINGTON (Reuters) - A gunman wounded a security guard on Wednesday at the headquarters of Family Research Council, a conservative Christian lobbying group, police said.

The male guard was shot in the arm when he confronted the gunman in the lobby of the building in downtown Washington, a police spokesman said.

Other guards wrestled the gunman to the ground and he was taken into custody. The wounded guard was taken to a hospital, where he is in stable condition, the spokesman said.

The weapon was recovered and the motive for the attack is unknown. The Federal Bureau of Investigation and police are investigating.

In a statement, President Tony Perkins said: "Our first concern is with our colleague who was shot today. Our concern is for him and his family."

Founded in 1983, the Family Research Council opposes same-sex marriage, abortion, embryonic stem-cell research and disputes that global warming is the result of human activity.

(Reporting by Ian Simpson; Editing by Vicki Allen)