BOULDER, Colo. (CBS4) – Police are searching for a dog and his owner involved in an attack.

The attack happened Tuesday at the Foothills Community Dog Park. Police say a pit bull-mix bit a pit boxer-mix and would not let go. The person with the boxer-mix stabbed the other dog with a pocket knife.

Both dogs weren’t seriously injured but officers want to find the pit boxer’s owner. Authorities say during the fight one of the dogs bit someone else who was trying to separate them. Health officials want to make sure the dogs are not carrying rabies.