A Northumbria police officer. Photo: X / Northumbria Police
A police office has been attacked and the property next to it set alight as protesters clashed with police in Sunderland during a demonstration linked to the Southport knife attack.
Clashes between the force and rioters led to three injured officers being taken to hospital, though one had since been discharged, Northumbria police said.
It follows beer cans and stones being thrown at police in riot gear outside a mosque, and other clashes between officers and demonstrators around the city.
Eight people have been arrested for a range of offences, including violent disorder and burglary.
Northumbria police Chief Superintendent Helena Barron said officers had been met with "serious and sustained" levels of violence, which was "utterly deplorable".
She said a full investigation was under way to identify those responsible for any criminal behaviour linked to the protests.
"I want to make it absolutely clear that the disorder, violence and damage which has occurred will not be tolerated," Barron added.
"The shocking scenes we have witnessed in Sunderland this evening are completely unacceptable."
Home Secretary Yvette Cooper said "criminals attacking the police and stoking disorder on our streets will pay the price for their violence and thuggery".
Police officers have had beer barrels thrown at them, as young men shouted "whose streets, our streets".
Some crowds have chanted in support of far-right activist Tommy Robinson, while others shouted Islamophobic slurs.
Cars in the city centre have also been targeted, with one overturned and set on fire.
Tyne and Wear Fire and Rescue Service confirmed it had been called out to the fire near the Sunderland Central Police office.
Rail and bus services have been halted with Tyne and Wear Metro operator Nexus saying it had been asked by British Transport Police to close Sunderland Rail Station at about 22:15 BST.
Bus operator Go North East said it would terminate all of its services short of Sunderland overnight, except for the service 20/20A which would terminate at Barnes.
The Omniplex cinema in the city was also forced to close during the evening in the interest of public and staff safety, it said.
Residents said they could still hear police helicopters in the sky past midnight.
The unrest follows riots in Hartlepool on Wednesday night, which Cleveland police said was linked to protests over the fatal knife attack on a group of children in Southport, Merseyside, on Monday.
North East Mayor Kim McGuinness said she was "appalled" by the scenes in Sunderland.
"Make no mistake, if your response to tragedy is to use it to commit violence, to abuse others, attack the police and damage property you stand for nothing except thuggery," she said.
"You don't speak for Sunderland. You don't speak for this region."
Sunderland AFC posted on social media: "Tonight's shameful scenes do not represent our culture, our history, or our people.
"Our great city is built on togetherness and acceptance, and Sunderland will forever be for all.
"We are stronger as one community."
Sunderland Central MP Lewis Atkinson said the police had his full support in response to the criminal "thuggery".
A crowd of about 200 anti-racist protesters also gathered outside the Abdullah Quilliam Mosque in Liverpool after rumours of a far-right protest there.
The group chanted "say it loud, say it clear: Refugees are welcome here".
Director of public prosecutions Stephen Parkinson said extra prosecutors had been called into work this weekend to deal with the disorder.
"We have deployed dozens of extra prosecutors who are working round the clock this weekend, supporting the police, and ready to make immediate charging decisions so that justice is swiftly delivered," he said.
This story was first published by the BBC