PHILADELPHIA — Two adult staffers were stabbed and wounded at a northeast Philadelphia middle school Tuesday while disarming a boy with a knife, police and the school's principal said.

Officers were called to Castor Garden Middle School shortly after noon and found a 63-year-old woman was stabbed in her left side and a 31-year-old woman in the right arm, police said.

The first victim was taken to a hospital where her condition wasn't immediately available; the second victim refused medical treatment.

Principal Shawn McGuigan said in a message to families that the victims are staffers at the school and that all students were safe following a school lockdown, WPVI-TV reported.

Deputy Commissioner Frank Vanore said a boy, who attends the school, pulled a knife out of his bag in a classroom. He said the staff members were alerted by other students and sustained “superficial” cuts while disarming the boy.

Vanore said the boy was in custody, and police are working with his parents.

Monique Braxton of the School District of Philadelphia said the student had gone through the school's metal detector “and it did not pick up the knife.” She said the district's Office of School Safety will investigate.