Police Barracks Shooting

Three A U.S. Marshals patrol along Mill Creek near Clarks Road in Barrett Township, Pa., Monday Sept 29, 2014, as the search for Eric Frein continues since the Pennsylvania State Police shooting at Blooming Grover Sept 12. Frein is a suspect in an ambush that killed a Pennsylvania State Police officer and critically wounded another. (AP Photo/Scranton Times & Tribune, MIchael J. Mullen)

(Michael J. Mullen)

BLOOMING GROVE, Pa. (AP) — State police searching for a man accused of killing a state trooper said Tuesday they found two pipe bombs in the Pennsylvania woods during their manhunt.

Lt. Col. George Bivens said the bombs were fully functional but not deployed. He says they could have been set off by either a trip wire or fuse, but appear to be among items that were hastily discarded.

State police say note the wire on the left side of explosive, that could be set off if trooper tripped on it. pic.twitter.com/ZCGnJuGYTn — Jon Meyer (@JonMeyerWNEP) September 30, 2014

Eric Frein, 31, has been on the run since Sept. 12, accused of killing one state trooper and wounding a second outside their barracks.

Authorities believe the self-taught survivalist is hiding in the thick woods near his parents' home in the Pocono Mountains.

Bivens says the bombs were found at a campsite apparently being used by Frein.

He also says there has been at least one credible sighting of Frein in the past 24 hours.