British Prime Minister Keir Starmer has condemned far-right violence that has seen gangs burn buildings, attack Muslims and ethnic minorities and clash with police over the weekend.

Speaking on Sunday shortly after rioters tried to set fire to a building housing asylum seekers, Starmer said: “Those who took part in this violence will face the toughest of laws.”

“The police will arrest you… I guarantee you will regret participating in this mess,” he said. “All reasonable people should condemn this kind of violence.”

Riots broke out in cities across the UK after fake news spread online that a suspect was being held in a knife attack at a children’s dance group in Southport on Monday, which killed three teenage girls. He was a Muslim migrant.