No injuries today in an explosion at the San Francisco Hall of Justice. Lieutenant Larry Minasian says an explosive device was placed in a paper dispenser in the first floor men´s bathroom. Police say the device could have been something as small as a firecracker or something more sophisticated. But Minasian says he thinks it was bigger than a cherry bomb. The explosion splintered a bathroom stall door and blew it off its hinges. Police have no suspects. The building was evacuated for about 20 minutes. The Hall of Justice houses courtrooms and police headquarters. The bathroom is in a secure area of the courthouse. Minasian says there are metal detectors at the door, but they wouldn´t detect explosives.