A U.S. congressional committee has met once again to investigate what one lawmaker calls Islamic radicalization in the United States – a topic that has drawn criticism from Muslims and other groups.

The congressman who heads the panel, New York Republican Peter King, says he called the hearings because al-Qaida is actively trying to radicalize young Muslims in the United States. He says the danger is “real and present.”

Wednesday's session, the second meeting on the topic, focused on Muslims in U.S. prisons, with testimony from law enforcement officials and others.

Critics say the hearings unfairly target Muslims and result in guilt by association for the entire Muslim community in America. They say Congress should investigate a broad spectrum of domestic terrorist threats, including anti-government hate groups and white supremacists.

The committee's top Democrat, Bennie Thompson of Mississippi, said it appears that instances of Islamic radicalization in prison are few, and that threats such as those posed by gangs, lone individuals, and right wing radicals should be pursued.

When King's committee met three months ago for its first hearing on Muslim radicalization, emotions ran high on Capitol Hill. Testifying before a large crowd of reporters, activists and spectators, the first Muslim American elected to Congress, Representative Keith Ellison of Minnesota, broke down in tears as he spoke.

King on Wednesday dismissed the protests and criticism in March over the first hearing as “mindless hysteria.”