Democratic lawmakers said Tuesday the Jena Six case shows the government needs to do more to combat racism far beyond a small Louisiana town where charges filed after a school fight garnered national attention.

"Racial discrimination in the criminal justice system is not unique to any one place, but is found in cities and towns north and south throughout our nation," House Judiciary Committee Chairman John Conyers said as he opened a hearing into the Jena case.

In Jena, six black teenagers were charged with the beating of a white student. The incident happened after nooses were hung from a tree on a high school campus there — a symbol of the violence of the segregation era.

Since the Jena case made headlines, there have been a number of other nooses found in high-profile incidents around the country — in a black Coast Guard cadet's bag, on a Maryland college campus, and, last week, on the office door of a black professor at Columbia University in New York.

Donald Washington, the U.S. attorney for the Western District of Louisiana, told the committee the Department of Justice has opened investigations into noose-hanging incidents in five states.

"A hanging noose is a powerful symbol of hate and racially motivated violence and it can in many circumstances constitute the basis for prosecution," said Washington, adding that in the Jena case, officials decided not to prosecute because the white students who had hung the nooses were juveniles.

Sheila Jackson Lee, a Texas Democrat who has traveled to Jena, charged the federal government has failed for years to fully enforce civil rights laws.

"Shame on you," said Jackson Lee.

The senior Republican on the panel, Lamar Smith of Texas, said, "more than anything what we need is an effort to reduce racial tension... What we do not need is stoking racial resentment."

New York-based civil rights activist Al Sharpton was scheduled to appear before the committee, but flight problems delayed him.

In prepared remarks submitted to the committee, Sharpton urged Congress to expand hate crime laws to deal more forcefully with noose-hanging incidents like the one in the Jena Six case in order to squelch what he called a sharp rise in racism.

Last week, one of the Jena Six, Mychal Bell, was sentenced to 18 months in jail after a judge determined he violated the terms of his probation for a previous conviction.

Racial tensions began rising in Jena in August 2006 after a black student sat under a tree known as a gathering spot for white students. Three white students later hung nooses from the tree. They were suspended by the school but not prosecuted.

More than 20,000 demonstrators gathered recently in Jena to protest what they perceive as differences in how black and white suspects are treated.