PHILADELPHIA — An eighth-grade girl stabbed a 13-year-old boy in the abdomen with scissors after an altercation in science class Friday, police and school district officials said.

The boy is in stable condition at a hospital.

The stabbing happened as students were transitioning to their next class just before 11 a.m. at the William Dick School, said Lee Whack, a spokesman for the School District of Philadelphia. The students had an altercation during science class, but the teacher de-escalated it and thought it was resolved, he said. The school serves students from kindergarten to eighth grade.

The girl has been arrested and the weapon was recovered, according to police. No details on the charges were released.

A student in the same class said that he heard the two arguing earlier and then saw the girl stab the boy as they were about to change classes.

He said he and other students helped take the boy to the office.