An armed man opened fire in a school in Rio de Janeiro on Thursday, killing 13 people and wounding 22 others before taking his own life, police said.

Authorities believe that the attacker was a former student at the school, while Globo News television reported that he was a student’s father, AFP said.

That man entered the school and started to shoot, Rio de Janeiro police spokesperson said.

TV Globo News showed images of the wounded being loaded into ambulances at the school in the western Rio neighborhood of Realengo.