(CNN) A portion of Baltimore's downtown was evacuated Monday following reports of a suspicious vehicle containing 1,000 gallons of gasoline.

Streets were closed and public transportation was cut off over four blocks near the Inner Harbor as police and fire units investigated a van in a parking garage.

Mayor Bernard C. "Jack" Young said no bomb was detected. "We are currently in the process of conducting precautionary sweeps in an effort to ensure public safety. These sweeps are expected to take several hours."

The vehicle "is not a threat and is in the process of being removed from the garage," Young later said.