A Pennsylvania State Trooper patrols a road on Saturday. (Butch Comegys/Scranton Times-Tribune via AP)

Several schools in northeastern Pennsylvania were abruptly closed Tuesday due to a possible sighting of a man that police have been hunting for more than a month.

Authorities have been scouring a stretch of the state for Eric Matthew Frein, 31, who police named as the “extremely dangerous” suspect in the killing of one state trooper and wounding of another last month.

Frein has been charged with shooting and killing Cpl. Bryon Dickson, a state trooper who was leaving the barracks in Blooming Grove, Pa., on Sept. 12. Frein also shot and seriously wounded Alex Douglass, another trooper who was arriving at the barracks, during the same ambush, according to police. Dickson’s funeral was held in Scranton, Pa., last month.

Police have said that Frein had training as a survivalist and had expressed a desire to kill law enforcement officers. As the manhunt intensified and Frein was identified, he was added to the FBI’s list of the 10 most wanted fugitives. The FBI said it is offering a $100,000 reward for information that leads to Frein’s arrest.

There were at least two reported sightings of Frein in recent days, according to the Associated Press. As a result, the Pocono Mountain School District closed all of its schools on Tuesday. The same district, which announced the closure shortly after 5 a.m. on  Tuesday, had also closed its 10 schools during the early days of the manhunt.

As the manhunt has continued for more than five weeks, there have been other sightings and possible indications of Frein’s presence. Police thought they saw him last month and said they have come across soiled adult diapers and empty packs of Serbian cigarettes as part of the search.

People in Barrett and Price townships had spent about a day under a warning to take shelter owing to concerns that Frein may have been in the area. Police also said they found pipe bombs that they said belonged to Frein.