JENA, La. — A judge today denied a request to release a teenager whose arrest in the beating of a white classmate sparked this week’s civil rights protest in Louisiana.

Mychal Bell’s request to be freed while an appeal is being reviewed was rejected at a juvenile court hearing, effectively denying him any chance at immediate bail, a person familiar with the case said. The person spoke on condition of anonymity because juvenile court proceedings are closed.

Earlier, Bell’s mother emerged from the hearing in tears, refusing to comment.

Bell, 17, was convicted of aggravated second-degree battery, which could have led to 15 years in prison. But his conviction was thrown out by a state appeals court that said he could not be tried on the charge as an adult because he was 16 at the time of the beating.

Yesterday, the case drew thousands of protesters to this tiny central Louisiana town to rally against what they see as a double standard of justice for blacks and whites. The march was one of the biggest civil rights demonstrations in years.

The case dates to August 2006, when a black Jena High School student asked the principal whether blacks could sit under a shade tree that was a frequent gathering place for whites. He was told yes. But nooses appeared in the tree the next day.

Three white students were suspended but not criminally prosecuted. A LaSalle Parish district attorney, Reed Walters, has said he could find no state law covering the act.

The incident was followed by fights between blacks and whites that culminated in the attack on Justin Barker, who was knocked unconscious on school grounds. According to court testimony, his face was swollen and bloodied, but he was able to attend a school function that night.

Five of the teens were originally charged with attempted second-degree murder — charges that have since been reduced for four of them. The sixth was booked as a juvenile on sealed charges.