LONDON — Within hours of a stabbing attack in northwest England that killed three young girls and wounded several more children, a false name of a supposed suspect was circulating on social media. Hours after that, violent protesters were clashing with police outside a nearby mosque. Police say the name was fake, as were rumors that the 17-year-old suspect was an asylum-seeker who had recently arrived in Britain. Detectives say the suspect charged Thursday with murder and attempted murder was born in the U.K., and British media including the BBC have reported that his parents are from Rwanda. That information did little to slow the lightning spread of the false name or stop right-wing influencers pinning the blame on immigrants and Muslims. “There’s a parallel universe where what was claimed by these rumors were the actual facts of the case,” said Sunder Katwala, director of British Future, a think tank that looks at issues including integration and national identity. “And that will be a difficult thing to manage.” Local lawmaker Patrick Hurley said the result was “hundreds of people descending on the town, descending on Southport from outside of the area, intent on causing trouble — either because they believe what they’ve written, or because they are bad faith actors who wrote it in the first place, in the hope of causing community division.” One of the first outlets to report the false name, Ali Al-Shakati, was Channel 3 Now, an account on the X social media platform that purports to …