A gunman who shot a security guard in the arm the offices of a conservative lobby group in Washington DC on Wednesday was carrying "additional rounds of ammunition", according to police.

Officers said the man was carrying a handgun and extra rounds of ammunition when he tried to enter the Family Research Council, NBC news reported. He was detained by guards and district police.

The suspect, identified by NBC sources are 28-year-old Floyd Corkins from Herdon, Virginia, walked into the building's lobby at around 10.45am. He fired at the guard after being challenged, hitting him in the arm. Police said the injured guard was among a group of people who managed to subdue the suspect following the attack.

"The security guard here is a hero, as far as I'm concerned," said DC police chief Cathy Lanier said. "He did his job. The person never made it past the front."

Lanier said the guard had confronted the gunman in the lobby of the building, asking him where he was going before being shot. She said the guard and others tackled the man to the ground and held him until police arrived.



Fox News reported that the suspect had "made statements regarding [the FRC's] policies, and then opened fire with a gun".

Some reports suggested the man was carrying Chick-Fil-A bags – the FRC's president Tony Perkins attracted some criticism last month after emailing members suggesting they should support Chick-fil-A's stance on gay rights.

"The police are investigating this incident," Perkins said in a statement on Wednesday. "Our first concern is with our colleague who was shot today. Our concern is for him and his family."

More than 20 different LGBT organisations from across the US put out a statement condemning the shooting. "We were saddened to hear news of the shooting this morning at the offices of the Family Research Council. Our hearts go out to the shooting victim, his family and his co-workers," it said.

"The motivation and circumstances behind today's tragedy are still unknown, but regardless of what emerges as the reason for this shooting, we utterly reject and condemn such violence. We wish for a swift and complete recovery for the victim of this terrible incident."