An Arizona school bus driver is under investigation for allegedly locking rowdy kids on board.

The driver claims he locked the children inside because they were being too loud and misbehaving, but parents who were at the bus stop waiting for their kids say it was an unjust punishment, reports CBS News correspondent Vladimir Duthiers.

Surveillance video shows the chaotic scene of kids crying and frantically pleading to get off the bus. Children pushed to the front trying to exit, but the driver wouldn't unlock the door.

"See, your parents are getting upset. You break that door; you're going to be buying a new one. Your kid will get off the bus when I am done with 'em," the driver said.

Nearly 40 children were inside.

Some parents tried to pry open the doors; others called 911.

"He won't let any of our kids out," parent Adam Kautman said to police dispatch. "The kids are crying. He's screaming at us."

Then the driver took off.

"He's actually driving away with all our kids," Kautman said. "He's got all our kids on the bus."

The driver took the kids back to Dysart Elementary School where they were released from the bus. No injuries were reported.

"I don't know if he went crazy, was going to crash into something because the way he took off he was speeding," Kautman said.

The school district launched an investigation and put the driver on administrative leave, but some parents said it's not enough.

"They're responsible for the lives of all those children on the bus to get home safely, and he did the exact opposite of that," Kautman said.

The superintendent of the school said this was not the bus driver's scheduled route, but that all drivers are responsible for children's safety. The driver has since resigned from his position.