A juvenile was being questioned in Montgomery County on Tuesday after a low-grade explosion – possibly from a firework or firecracker – went off outside the county’s public safety building. No injuries were reported.

The loud noise was first reported at 11:09 a.m., according to a county police spokeswoman. County bomb investigators inspected the parking lot, and found remnants of the small explosion. The county’s public safety building is about one mile east of the intersection of Darnestown and Quince Orchard roads in Gaithersburg.