SEATTLE -- A 12-year-old boy is in a Seattle hospital after being attacked on Monday.

The attack occurred just after noon Monday at the Southwest Community Center near the 2100 block of Southwest Thistle in West Seattle, said Mark Jamieson with Seattle Police.

Officers believe the boy was beaten by another student, a girl of similar age, with a backpack filled with a rock or rocks, Jamieson said.

The assault took place near the playground, investigators said, and the center's staff members found the boy was found lying, unconscious, on the pavement.

By the time medics arrived, the boy was able to talk and move around. He was taken to Harborview Medical Center, where his condition is not known.

The boy is said to attend Denny Middle School, where school is still in session. It's unclear why the students were at the community center during school hours.

Police have spoken with the girl accused of the attack. A motive has not been determined.