A bomb threat disrupted operations at the Allegheny County Courthouse and the Municipal Courts Building for about an hour and a half Monday morning.

Allegheny County Sheriff William Mullen said an anonymous caller placed a phone call to the Municipal Courts Building at 7:25 a.m. claiming a bomb was placed in that building as well as the Courthouse.

People with business in the Courthouse were kept out of the building and employees were evacuated.

Bomb dogs were brought in from other jurisdictions to speed the search.

At 9:37 a.m., the courthouse was cleared.

Mullen says the threat cost untold man hours of investigation and security resources.