DUNCANVILLE, Texas (AP) — Police shot and killed a man who fired gunshots at a Dallas-area gymnasium where about 150 children were attending a day camp, authorities said.

No children, staff or officers were hurt in the shooting that happened at about 8:45 a.m. at the Duncanville Fieldhouse, police said.

The man entered the field house lobby with a handgun and fired a shot during a discussion with a staff member, Duncanville Assistant Police Chief Matthew Stogner said.

The gunman then tried to enter a classroom containing children, but the door was locked, Stogner said. He fired one shot into the door, Stogner said. The man then went to the gym, which also contained children, at which point Stogner said police arrived and shot the man in an exchange of gunfire.

Police have not yet identified the person or revealed a motive.

Stogner said police arrived within two minutes of being contacted.

All children attending the camp were moved to a nearby recreation center for reunification with their parents.