An investigation is underway in Leeds after police officers armed with riot shields had fireworks and missiles thrown at them on Bonfire Night.
A helicopter was sent to the scene and a total of 15 males aged 11 to 23 have been arrested on suspicion of violent disorder.
Officers were responding to an emergency call in the Harehills area of the city just after 8pm. They were confronted by "a group of youths" throwing fireworks, missiles and bricks.
Four officers received injuries during the incidents, two were treated at hospital but none were seriously injured.
A number of local shops and police vehicles were also damaged,
The force condemned the behaviour with the following statement: