A northeastern Pennsylvania school district is closed Tuesday following at least two reported sightings of the suspect in a deadly state police ambush.

Officials in the Pocono Mountain School District announced the decision to cancel classes shortly after 5 a.m. Tuesday.

In the latest reported sighting, a local law enforcement official is believed to have spotted suspect Eric Frein near the Swiftwater Post Office on Monday, leading to an intensive police search. The post office is less than a half-mile from a high school, junior high and elementary school campus.

"He lost visual contact with the man through the woods," Trooper Tom Kelly said Tuesday morning. "A search of the area was conducted but no one was located," 

The sighting was three days after a woman said she saw Frein near Pocono Mountain East High School.

Frein, 31, is charged with opening fire outside the Blooming Grove state police barracks on Sept. 12, killing a trooper and seriously wounding another. Authorities had been searching for him in the woods around his parents' home in Canadensis but shifted their primary search area 5 or 6 miles to the southwest after Friday night's sighting. Lt. Col. George Bivens said over the weekend that police have put a "tremendous amount of pressure on him" and likely forced him to move.

The high school, Frein's alma mater, and all other schools in the Pocono Mountain School District were open Monday but took extra precautions in light of the most recent sighting.

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, besides the high school, includes a junior high and elementary school.

On Monday, as police ramped up their search efforts in the area in response to the latest possible sighting, district officials moved outdoor after-school athletic practices to another campus. District officials later posted on its website a statement saying students will remain inside on Tuesday.

State police have said they believe Frein, a self-taught survivalist, has a hatred of law enforcement and wants to target police rather than the general public.

State police said Monday that blood found at two homes in the search area is not linked to Frein. DNA testing ruled out any link to Frein in blood droplets found on a covered porch in the area. Material found on a back door at a second home near the first turned out not to be human blood.

Police believe Frein could be breaking into vacant cabins or vacation homes to look for food or take shelter.

The Associated Press contributed to this report.