ALEXANDRIA, La. (AP) — A Colfax, La., man who allegedly drove his pickup truck with a pair of nooses hanging from the back bumper past a group of black civil rights marchers, was indicted on federal hate crime and conspiracy charges, the U.S. Attorney for the Western District of Louisiana said Thursday.

Jeremiah Munsen, 18, was arrested in September when Alexandria police allegedly found hangman’s nooses dangling from the rear of his pickup truck after he drove past a crowd of people who had attended a civil rights march in Jena, La., earlier in the day.

The indictment alleges that Munsen, along with another individual, conspired to threaten and intimidate the marchers.

In addition to the civil rights conspiracy charge, the indictment charges the defendants with a federal hate crime.

‘‘It is a violation of federal law to intimidate, oppress, injure or threaten people because of their race and because those people are exercising and enjoying rights guaranteed and protected by the laws and Constitution of the United States,’’ Washington said.

At the time of the arrest, Munsen, who is white, was booked on state charges of inciting a riot, driving while intoxicated and contributing to the delinquency of a juvenile — a 16-year-old boy from Dry Prong, La., who was with him.

Nooses figured into the controversy that drew tens of thousands of people to Jena, a small town about 40 miles northeast of Alexandria.

Three white students were suspended but not criminally prosecuted for putting nooses in a tree at Jena High school at the beginning of the school year in 2006.

In December, six black students were charged with beating a white student, Justin Barker, knocking him unconscious.

Five were originally charged with attempted second-degree murder — leading to accusations of overly harsh prosecution bcause of race. The charges have since been reduced.

‘‘I think that this indictment is appropriate and a step in the right direction,’’ the Rev. Al Sharpton, who helped organize the march to Jena last September, said in a statement late Thursday.

‘‘I hope this is a signal that the Justice Department will now take hangman’s nooses and hate crimes more seriously. If they had prosecuted the white students that hung the noose in Jena we may never have had to raise the national outcry that we did because our protest was over why some are prosecuted and others excused. Hopefully this indictment means the beginning of a change in that imbalance.’’