A pair of pit bulls chased students into a restroom at a middle school Friday morning and mauled an 11-year-old girl, police said.

"The dogs immediately attacked her," said San Fernando Police Chief Anthony Alba. "She had dog bites all over her body."

The girl, whose identity was not immediately released, managed to run out of the restroom and a custodian hit the dogs with a trash can and they broke off the attack, Alba said.

She had a badly bitten left leg and was flown in "pretty serious condition" to a hospital in Los Angeles, Alba said. The wound was not considered life-threatening, he said.

One dog attacked an arriving motorcycle officer, who was not hurt, before it was shot with a bean bag round by another officer, Alba said.

The dogs then ran back to their yard, which was only a few blocks away, the chief said.

The 18-year-old owner of the dogs, Orlando Vasquez, was arrested and held in lieu of $25,000 bail.