Gangs of bikers and crowds of youths throwing fireworks caused Halloween chaos for police across the country.
More than 200 motorcyclists gathered for a "Halloween ride-out" in Solihull and Birmingham on Monday evening, while in Leeds a group of around 50 racing off-road motorcycles and quad bikes brought a busy road to a standstill.
Police were pelted with fireworks in multiple incidents, with one officer narrowly avoiding being hit by an explosive in Tottenham, north London, the Metropolitan Police said.
A police van is pelted with a volley of fireworks in Birmingham (West Midlands Police/PA Wire)
The Police Federation of England and Wales (PFEW) condemned the attacks and called for appropriate punishments for those who assault officers .
At least seven people were arrested and 10 motorcycles seized following the bike gathering in Birmingham, West Midlands Police said.
The riders caused "chaos" as they darted between traffic, jumped red lights and performed stunts on busy main roads.
At one point up to 100 masked bikers surrounded a police van in Yorkminster Drive in Chelmsley Wood, while the fire service also reported that a group had attempted to stop them from responding to an emergency call.
West Midlands Police Chief Inspector Jack Hadley described the incident as "outrageous" and "totally unacceptable".
"This wasn't a rally of bike enthusiasts - this was loutish, criminal behaviour," he said.
"Bikers were riding without lights, at speed, dangerously, pulling wheelies in the street, mounting pavements and damaging vehicles."
Police closed Kirkstall Road in Leeds for 90 minutes on Monday evening as they waited for a gang of around 50 bikers to disperse following a similar event, which is believed to have been organised on social media.
Witnesses described the scenes as "utter chaos" and "madness" and compared them to those in the Mel Gibson film Mad Max.
A 26-year-old man, from Leeds, was arrested on Tuesday morning in connection with the incident and remains in police custody, West Yorkshire Police said.
Scotland Yard said one youth had been detained in relation to the attack on police in Tottenham.
Footage from the dashboard camera of a car being driven by neighbourhood watch group Shomrim showed a firework fly past a running Metropolitan Police officer.
The rocket then ricocheted and exploded next to a police car in Fladbury Road at around 9.40pm but n o officers were injured, MPS Haringey said.
There were similar scenes in Coalisland as fire crews came under attack from youths with fireworks, with hostile crowds forcing them to withdraw from incidents in Rostrevor and Newry, Northern Ireland Fire and Rescue Service said.
Police were also targeted as they attempted to disperse a crowd of around 100 youths in Cheshunt, Hertfordshire.
The group threw fireworks at officers, parked cars and houses in the Rosedale and Andrews Lane areas of the town, Hertfordshire Police said.
Some 40 officers attended the incident, which took several hours to defuse, and a number of arrests were made, a spokesman said.
Calum Macleod, vice chair of the PFEW, said: "Attacking a police officer in any way is to attack those who put their lives on the line to protect others - like any profession, they have the right to feel safe when they go work.
"But the harsh reality is that an officer is assaulted every 22 minutes across England and Wales."
He added: "Statistics show that most crime occurs at night when forces are even thinner on the ground. This leaves officers more vulnerable to being assaulted - as we saw last night.
"Yet what we are seeing is a judicial system that doesn't appear to act as a deterrent for offenders.
"We continue to campaign for changes to ensure that those found guilty of assaulting police officers are sentenced appropriately."
Gwent Police urged those celebrating Halloween and Bonfire Night to use fireworks in a "responsible and adult manner" after seven people were arrested and commercial-size fireworks were confiscated in Newport on Monday night.
The trouble came amid a series of attacks involving fireworks.
Footage released by West Midlands Police shows a police van being hit by a volley of fireworks from Balsall Heath Park in Birmingham on October 22 at around 8.30pm.
A 16-year-old boy was arrested on suspicion of public order offences and criminal damage on October 26 and has been released on bail, police said.
Video posted on social media by neighbourhood watch group Shomrim shows the moment a lit firework was directed at a group of children in Stamford Hill, north London.
An eight-year-old girl suffered minor burns on her leg as a result of the incident at around 7.45pm on October 21, but was treated by a relative at the scene, a spokesman for Shomrim said.
David Lammy, Labour MP for Tottenham, criticised those involved in the attack on officers in north London.
He said: "I condemn these highly dangerous acts of stupidity in the strongest terms possible.
" It is totally unacceptable for people to behave in this manner and I am thankful that no title police officers were hurt last night.
"I hope that the foolish actions of a small minority do not ruin events planned in the community to celebrate Guy Fawkes Night in the coming days."