Children bitten by a dog had to be taken to hospital after being attacked by the animal in a park.
The dog bit a number of children in a park in Blyth, Northumbria, on Wednesday evening, police said.
None of the injuries was thought to be serious but paramedics and police attended the scene.
Officers are keeping the dog in secure kennels until they can find its owner.
A Northumbria Police spokeswoman said: “At around 6.30pm on Wednesday, police received reports of a dog that had bitten a number of children in the park next to Burns Avenue in Blyth.
“Emergency services attended and police were able to bring the animal under control.
“A number of children were taken to hospital with bite wounds but none of the injuries are thought to be serious.
“Police remain in the area to reassure the local community and carry out inquiries to locate the animal’s owner.
“The dog is currently at secure kennels while officers carry out their investigation.”