Crowds clashed with police outside a Southport mosque on Tuesday night, following Monday’s attack, in which three girls were killed at a Taylor Swift-themed holiday club.
The unnamed 17-year-old suspect in the case is from Wales, Merseyside Police has said, but false claims had spread online that he was an asylum seeker who had arrived in the UK by boat.
A police van was set on fire, as officers in riot gear clashed with masked youths who threw missiles at the officers.
Police were said to be preparing for the possibility of a far-right rally on Tuesday ahead of the clash.
Speaking to broadcasters on Tuesday night, Home Secretary Ms Cooper branded the incident “a total disgrace”.
She said the community had thanked the police for their “heroism”, adding: “That is why it is so appalling to now see those same police facing violent attacks from thugs on the streets who have no respect for a grieving community.
“It is a total disgrace. Frankly, this is a time when everyone should be showing respect for a community and for the police.”
She went on: “Frankly the scenes of thuggery that we have seen on the streets of Southport this evening bear no relation to the way in which the Southport community has been coming together to support each other and to support grieving families.”
In the Commons she had earlier urged social media companies to “take some responsibility” for speculation in the aftermath of the attack, as the case was “about children and their families who will be grieving”.
Shadow home secretary James Cleverly called for people not to “get involved in the grief of others” by sharing misinformation relating to the Southport attack on social media.
“Enough people are already distressed without their distress being amplified by speculation and gossip online,” he added.
Home Secretary Yvette Cooper and Southport MP Patrick Hurley look at tributes near the scene of the attack in Hart Street, Southport (James Speakman/PA)Ms Cooper’s intervention aimed at quelling social media rumours came after Downing Street urged the public to avoid “unhelpful” speculation about the attack, amid concerns that misreporting online could inflame community tensions.
Asked whether the Prime Minister would appeal for calm if a rally were being planned, Sir Keir Starmer’s official spokesman said: “Of course, people should listen the police, they should not do anything that is going to make the police’s job harder to manage the situation, to conduct their investigations.
“It is unhelpful to speculate on things like the motive and the circumstance around this.”
Alice Dasilva Aguiar, nine, Bebe King, six, and Elsie Dot Stancombe, seven, were named as the three girls fatally stabbed in the incident on Monday.
Eight other children suffered stab wounds and five are in a critical condition, alongside two adults who were also critically injured, police said.
A 17-year-old boy, who cannot be named for legal reasons, remains in custody accused of murder and attempted murder following the attack at the dance studio in Hart Street.
Bebe King, Elsie Dot Stancombe and Alice Dasilva Aguiar were fatally stabbed in the attack (Family handouts/PA)
Police said a name shared on social media in connection with the suspect is “incorrect”, adding: “We would urge people not to speculate on details of the incident while the investigation is ongoing.”
Although the motive for the attack is unclear, it is not believed to be terror-related according to police.
The force said the suspect, who was born in Cardiff, is from the village of Banks, just outside Southport, and a road in the area was cordoned off by detectives on Monday afternoon.
