"During that time, one of our canine officers was assisting, and the canine accidentally came out of the vehicle," Dunn said. "Officers were able to get the canine back into the vehicle, and we don't know how many, if any, people were bitten."
Televised video showed at least one man with apparent bite marks on his back, and a German shepherd biting the arm of another person.
Dunn said officers did not purposely let the dog loose on the agitators, who pulled a trash bin into the street and set its contents on fire. A police car was damaged, Dunn said.