Fireworks were launched at police officers and firefighters dealing with Bonfire Night callouts in several UK cities.
Eight people were detained in Liverpool on Saturday, three of whom remain in custody for questioning, after fireworks were seemingly aimed at vehicles in the area around Princes Park.
A police officer was injured during the chaotic scenes, which saw several wheelie bins and electric scooters left completely burnt out.
In Leeds riot officers had to be called in as fireworks were thrown into crowds of bystanders in the city's Hyde Park area.
Sharing footage of the disorder on Twitter, Jack Naylor wrote: "A short story depicting what it’s like to live in Leeds on bonfire night.
"Fireworks need stricter regulations. This area is predominantly students but there are families with young children that live here. This is not okay."
Police initially arrived to deal with a fire but had to run through the street as they were pelted with fireworks. Three people were arrested on suspicion of arson.
Chief Inspector Duncan Swan said: “This reckless behaviour caused a great deal of distress to road users in the area, and resulted in damage to bins and vehicles, and an injury to one of our officers.
“Such behaviour can cause danger and risk injuries, and we’ll investigate thoroughly to ensure all of those we can identify and brought to account.”
In Bradford, four people were arrested and later released on bail over attacks on police and fire service vehicles, on one of the busiest nights of the year for emergency service personnel.
Inspector Paul Riley said: "Assaults on emergency workers are totally unacceptable and will not be tolerated.
"We will work with partners to take positive action on these types of incidents."
Fireworks were launched at passing motorists in Manchester’s Cheetham Hill area, while a firework was thrown at firefighters dealing with a bonfire in Eccles.
In Salford a firework was put through a letterbox, starting a small fire in the hallway which firefighters had to extinguish.
In the North East, Cleaveland Fire Brigade personnel had fireworks and rocks thrown at them while doing their jobs.
Meanwhile in Edinburgh’s Niddrie area people were urged to stay at home after a road was blockaded with fire while motorcyclists raced each other.
Footage on social media showed a motorbike gang racing through the streets as fireworks were launched along the ground, seemingly aimed at other people’s vehicles.
A police vehicle was also hit with a Molotov cocktail, although no one was injured, Police Scotland said.
Condemning the violent behaviour, Edinburgh City Council leader Cammy Day said: “The scenes the local community had to suffer and witness in Niddrie last night were disgraceful and disgusting.
“Police responded swiftly and we have been supporting them and our other emergency partners following the firework-related disorder and antisocial behaviour that took place last night.
“It’s only a minority of people responsible for this inexcusable behaviour and I’m sure they will feel the full force of the law.
“It’s extremely fortunate that no-one was seriously injured as a result – attacks on the emergency services are despicable and reckless behaviour like this endangers lives.