King has been criticised by religious and civil rights leaders as going on a witch hunt for targeting one community [EPA]

Al-Qaeda is targeting Muslim Americans for recruits to terrorism and the community must do more to combat radicalisation, a US politician has said as he opened hearings in Washington that have been criticised as a witch hunt.

Peter King, the chairman of the House of Representatives Homeland Security Committee who called the hearings, has accused the Muslim community of refusing to co-operate with law enforcement and charged that preaching in some US mosques was leading to radicalisation.

"To combat this threat, moderate leadership must emerge from the Muslim community," King said. "Today, we must be fully aware that homegrown radicalisation is part of al-Qaeda's strategy to continue attacking the United States."

Democratic representative Keith Ellison, the first Muslim to serve in the House, castigated the committee for its approach and broke down crying as he recounted the story of a 23-year-old Muslim paramedic who died when he responded to the September 11, 2001, attacks in New York City.

"After the tragedy, some people tried to smear his character solely because of his Islamic faith," he said on Thursday.

"Some people spread false rumours and speculated that he was really with the attackers because he was a Muslim."

He said that the young man should be identified as someone "who gave everything for his fellow Americans" rather than solely as a member of a religion or ethnic group.

'Good name'

King has been criticised by religious and civil rights leaders for focusing on a single community.

The New York congressman denied accusations that the hearings were "radical or un-American" and said there was no comparison between the threat by al-Qaeda and neo-Nazis, environmental extremists and other "isolated madmen".

He defended the hearings, citing the open attempts by al-Qaeda fighters to recruit its members to launch attacks.

John Dingell, Michigan representative and the senior Democrat in the House, urged King and the committee to ensure that their investigation would not "blot the good name or the loyalty or raise questions about the decency of Arabs or Muslims or other Americans".

The focus of the hearings have also raised concerns within the administration of Barack Obama, the US president, to the point that a senior White House official was dispatched to speak to Muslim leaders in Virginia where he told them they were "not part of the problem".

Eric Holder, the US attorney general, took a veiled swipe at King on Wednesday, saying the focus by law enforcement was on individuals rather than an entire community because "we don't want to stigmatise, we don't want to alienate entire communities".