The United Kingdom woke up Sunday morning to city streets covered in debris and smoldering rubbish as a weekend of far-right, anti-immigration demonstrations — stoked by conspiracy theories spread on social media — erupted into violence in seven cities across the nation.

Police arrested at least 100 people, and riot police wearing helmets and holding shields came out in force as Prime Minister Keir Starmer pledged to take action against “extremists.”

On Saturday, groups in Leeds waving St. George’s Cross flags, England’s national flag regularly flown by far-right groups, shouted “Muslims off our streets,” pairing it with a slur suggesting they were criminal child abusers. In the city of Hull, rioters threw bottles and smashed a window at a hotel housing asylum-seekers as demonstrators clashed with police.

What started as targeted anti-immigration demonstrations quickly descended into directionless disorder. A library in Liverpool, reopened in 2023 as an “education to employment” service for people of all abilities, was set ablaze.