Dozens of FBI agents are seizing documents and electronic equipment at the city hall of a financially struggling town in northern Puerto Rico.

The special agent in charge of the FBI's San Juan division said Tuesday that agents were serving a search warrant at the government offices in Toa Baja. Douglas Leff said the FBI would turn over potential evidence to the U.S. Attorney's Office.

The reason for the search isn't clear. The FBI did not release further details.

The Internal Revenue Service recently froze Toa Baja's accounts because of a $1.5 million debt and the city government temporarily shut down most operations.

Mayor Jorge Ortiz said he is cooperating and declined further comment.