ADAMS TWP — A stranger was found on school grounds at the Mars Primary Center on Tuesday. Mars Superintendent William Pettigrew sent a letter home to parents at dismissal Tuesday informing them of the situation. Pettigrew said Wednesday morning that the district's private security firm officers were completing their routine daily check of the school grounds when they came around a corner and saw a man who did not belong at the school. The security guard shouted at the man to identify himself and asked what he was doing there, but the man ran away. Pettigrew said per district procedure, the guard ran inside the school and dialed 911. He said Adams Township officers, who were on campus at another school performing routine arrival duty, were on the scene within minutes and began searching for the man. Pettigrew said police did not find the individual. He said Adams police officers, along with regular security guards, would remain on the school's property for the remainder of the week during school hours to ensure the safety of the district's youngest students. The primary center, which is on Route 228 just west of MHY Family Services, educates students in kindergarten and first grade. Assistant Police Chief Shawn Anglum of the Adams Township police said Wednesday morning that no arrests had been made. He said other information was unavailable. The incident came on the heels of the Dec. 14 shootings in Connecticut that killed 20 first-graders. “Mars School District strives to remain proactive in the protection of its students and employees,” Pettigrew told parents in the letter, which was also posted on the district's website. “The district will keep you informed of any additional information regarding this incident as it becomes available.” Pettigrew thanked parents for their patience and cooperation in the matter.