PHILADELPHIA – Police and school officials are investigating how a Pennsylvania 7-year-old got her hands on hypodermic needles, and why she chased and poked her classmates with them at school.

Parents of students at George Meade Elementary School in Philadelphia’s Spring Garden neighborhood were outraged to learn Thursday that five students were stuck with needles on Tuesday, alleging district officials never notified them of the incident, ABC 6 reports.

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“We didn’t know about it until this morning,” parent Stacey Smith said as she dropped her child off at the school Thursday, adding that she never received a notice from school officials.

“To see it on the news is a shock,” another parent, Hakim Bryant, told the news site.

Meade officials confirmed that five students were stabbed with a hypodermic needle a 7-year-old student brought with her from home, though it remains unclear if the needles were sanitary.

Asa Carey told ABC 6 his little sister was in the classroom when the incidents occurred, but was not among the students stabbed.

“My little sister was telling me about the little girl was running and chasing the little kids, and they were screaming and telling the teacher to come here she has a needle,” Carey said.

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Another student told the site the girl seemed to think the ordeal was a game.

Lashonda Peterson said her 8-year-old daughter was among the students attacked and she didn’t think the “game” was very fun.

Peterson’s daughter is now undergoing a series of tests to determine whether she may have been infected.

“Now I have to worry about if the needle was clean or if the needle was dirty,” Peterson said. “I hope it was clean!”

Fox 29 reports school officials said multiple needles were involved in the incident, though they were unsure how many.

“People are also concerned that the incident happened between 8:30 a.m. and 11:15 a.m. Tuesday morning, however officers weren’t notified until almost 5 p.m.,” the news site reports. “It’s unclear why it took the school more than 5 hours to notify the Philadelphia Police Department because investigators say that the needles used were turned in to a lunchtime aide and subsequently handed over to school police.”

Philadelphia police are interviewed students and parents as part of its ongoing investigation, and are attempting to determine if the incident was a result of adult negligence, ABC 6 reports.

Police told the site the 7-year-old girl who allegedly attacked her classmates is too young to face criminal charges, and school officials did not offer any insight into what, if any, discipline the student received.

District officials allege they immediately contacted the parents of students involved in the attack, and parents of other students in the area the next day. Officials also allege to have sent letters home to parents.