By Reuters

LONDON — Police arrested dozens of people after protests across parts of England and Northern Ireland turned violent on Saturday, as the government pledged tough action against those it said were exploiting the murder of three girls to stir up disorder.

Violent protests involving hundreds of anti-immigration groups have erupted in towns and cities across Britain after three girls were killed in a knife attack at a children’s dance class in Southport in north-west England last week.

The murders were seized on by anti-immigrant and anti-Muslim groups as misinformation spread that the suspect was a radical Islamist migrant. Police have said the suspect was born in Britain. Media reports have said his family was Christian.

On Saturday, violent disorder broke out in cities around the country, including Liverpool, Bristol, Hull and Stoke-on-Trent, as well as the town of Blackpool, with local police saying they had arrested at least 87 people. There was also unrest in Manchester and Belfast.

Shops and businesses were vandalized and looted, a library in Liverpool was set on fire and several police were injured, police statements said.

“Criminal violence and thuggery on our streets will not be tolerated,” interior minister Yvette Cooper said late on Saturday.

“Police forces have my full support in ensuring that those who engage in criminal disorder face the strongest possible penalties.”

Saturday’s protests were the most widespread after several days of disorder following the murders. Prime Minister Keir Starmer has said they are the result of deliberate actions by the far-right, coordinated by a “group of individuals who are absolutely bent on violence,” rather than legitimate protest.

The last time violent protests erupted across Britain was in 2011 when thousands of people took to the streets after police shot dead a Black man in London.

There are more demonstrations planned for Sunday, based on messages circulating on social media.