Twelve children were injured Monday when a dog got loose on the playground of Fillmore Elementary School at 5200 S. Blackwelder in Oklahoma City and began attacking the children. There were 28 children on the playground at the time. Some children were bitten and some were injured trying to run away. The dog ran into the school and was tackled by a teacher. It was caught and turned over to Animal Control officers. Five children were taken to the hospital by ambulance. Seven were taken by their parents. Police now are trying to figure out where the dog came from.