State police evacuated the state Capitol building in Harrisburg after threats were phoned in to a government official.
Bomb-sniffing dogs were scouring the building, as authorities told reporters to "Take your keys and go now."
Governor Corbett was not in building but was in Harrisburg at off site meetings. He was notified about threat.
No other details were immediately available.
The Capitol was cleared of personel shortly after 5:15 after receiving what state police called a "very credible threat."
"An individual called twice about an explosive device and we decided to have police sweep the building," said Troy Thompson, spokesman for the Deptartment of General Services.