Metro transit police caught a man trespassing on Sunday afternoon in the Royal Street Bus Garage in Alexandria, which is closed on weekends.

When the man told police he had been mixing chemicals in the garage, police and Alexandria fire department personnel launched a search for hazardous materials which shut down streets in the surrounding area.

Roads within at least one block of the intersection of North Royal and Pendleton Streets were closed to accommodate the fire equipment, Alexandria police spokeswoman Crystal Nosal said. Alexandria police officers knocked on residents’ doors to ensure them that the neighborhood was safe despite the disruption.

The trespasser was taken into custody, and it was still unclear who he was or why he said there were dangerous chemicals.

Officers and fire department officials found nothing dangerous in their search, said Metro spokeswoman Caroline Laurin.