Baltimore County police are investigating a "possible bias incident" after a rock was thrown through a window of a Muslim community center in the southwest neighborhood of Riverview.

Police spokeswoman Detective Cathy Batton said a rear window was reported broken at the Bab E Mustafa Community Center on Hollins Ferry Road between Monday evening and noon Tuesday. The cost to repair the damage was put at $100, she said.

She said police were looking into the possibility of bias as a motive chiefly because no other buildings in the area were damaged, and because the person making the complaint said that in the past, young people have shouted slurs at the building during prayer sessions.

Batton said the police have no other reports of vandalism or harassment. She said decisions about whether to charge a hate crime would be made by the state's attorney.

The Council on American-Islamic Relations, a civil liberties and advocacy group based in Washington, called the Baltimore office of the FBI on Thursday morning to ask for an investigation, said Ibrahim Hooper, CAIR's communications director. Reached late Thursday afternoon, FBI spokesman Richard Wolf said he had no information about the incident.

Hooper said he had not talked with anyone at the center. Members of the center could not be reached for comment.

Capt. John A. Spiroff, who heads the Wilkens Precinct, said he had asked officers to make more frequent checks on the community center, which he described as a quiet place that has been in operation at least a year.