Ambulance paramedics rushed to Moreton Downs State School at Deception Bay, where the boy's calf was skewered by a piece of steel reinforcement.

The boy was playing on concrete when the accident occurred about 9.15am, a Department of Community Safety spokesman said.

The steel rod was protruding from the concrete.

"It looks like he has tripped over and as he fell, it went through his lower leg," he said.

The boy has been taken to the Redcliffe Hospital in a "distressed" state.

The school, on Parsons Boulevard, has refused to comment, however an Education Queensland spokeswoman said authorities were waiting on a report from teaching staff before releasing a statement on how the accident happened.