PORTLAND – A suspicious substance found inside a Portland post office Friday evening turned out to be harmless, authorities said.

The building on Forest Avenue was evacuated at about 5:30 p.m. after the substance was reported by a postal worker. About 125 people were quarantined on buses for five hours.

Police were called after a powdery substance was discovered when a package was torn open on postal equipment. The building was evacuated and the area was blocked off.

Portland police and fire departments and the FBI were called to the scene.