Butch Comegys, Associated Press
A Pennsylvania State Trooper searches the woods near Lower Swiftwater Road in Swiftwater, Pa on Saturday, Oct. 18, 2014 during a massive manhunt for killer Eric Frein. A northeastern Pennsylvania school district opened with tightened security Monday after the suspect in a deadly police ambush was believed to have been spotted near one of its campuses.

A northeastern Pennsylvania school district opened with tightened security Monday after the suspect in a deadly police ambush was believed to have been spotted near one of its campuses.

A woman out for a walk Friday night spotted a rifle-toting man with a mud-covered face near Pocono Mountain East High School in Swiftwater. State police believe the man was Eric Frein, who has eluded capture despite an intense manhunt in the Pocono Mountains.

The high school and all other schools in the Pocono Mountain School District were open Monday.

Additional officers from the Pocono Mountain Regional Police Department were stationed at the district's Swiftwater campus to supplement the lone police officer who normally patrols that location, which, in addition to the high school, includes a junior high and elementary school.

Pennsylvania State Police did not recommend that schools close, district spokeswoman Wendy Frable said.

"We would not bring the students in if we did not have reassurance from police they felt the campus was safe," she said Monday.

The district will not have attendance figures until Monday afternoon, but anticipates that some students will have stayed home, she said.

State police Lt. Col. George Bivens said Saturday that authorities do not make a recommendation about whether to close schools, but provide as much information as possible to school officials so they can make their own decision.

Schools closed for several days early in the search because state police had closed roads and buses were unable to provide transportation.

Frein, 31, is charged with opening fire outside the Blooming Grove state police barracks on Sept. 12, killing one trooper and seriously wounding a second. State police have said they believe the self-taught survivalist has a hatred of law enforcement and wants to target police, not the general public.

Authorities had been searching for Frein in the woods around his parents' home in Canadensis, but shifted their primary search area five or six miles to the southwest after Friday night's sighting.

"I think we've kept a tremendous amount of pressure on him and I think that likely had some bearing on where he's at now, assuming that it is him," Bivens said.

State police are awaiting DNA results to confirm the presence of blood that two residents of the Cresco area reported finding outside their homes last week, and to see if it's a match to Frein.

Police believe Frein is breaking into vacant cabins or vacation homes to look for food or take shelter from the elements.