Kids playing with shell killed in blast

Unexploded ordnance detonated Saturday in southern Afghanistan killing at least four children and injuring three others after the kids brought it inside their school, police and a doctor said.

The incident in Helmand province happened when the children discovered an unexploded shell and brought it inside their religious school and started playing with it, according a statement from the provincial police chief 's office.

The children were ages 7 to 14 and at least three others were injured, according to the police statement.