Protesters attacked police and started fires in the northeast English city of Sunderland on Friday as violence spread to another northern city following Monday’s killing of three children in Southport.

Anti-immigrant demonstrators threw stones at police in riot gear near a mosque in the city before overturning vehicles, setting a car alight and starting a fire next to a police office, the BBC said.

Northumbria Police Chief Superintendent Helena Barron said in a statement, “The safety of…