At least two children died and nine others were injured in a knife attack at a Taylor Swift-themed event in northwest England on Monday, police said.

Police have arrested a 17-year-old boy in connection with the stabbing incident in Southport.

Police said he is currently in custody and will be questioned over the attack.

" At this early stage, enquiries are ongoing to establish the motive for this tragic incident and we would urge people not to speculate while the investigation is ongoing," Merseyside Police said in a statement.

Police said the incident was not currently being treated as terror-related.

Chief Constable Serena Kennedy said in a statement: "Nine other children have been injured, and six of them are in a critical condition, all those injured have suffered stab wounds sustained during the attack. Two adults are also in a critical condition after being injured during the incident."

"It is understood that the children were attending a Taylor Swift event at a dance school when the offender, who was armed with a knife, walked into the premises and started to attack those inside.  We believe that the adults who were injured were trying to protect the children at the time they were attacked," the cop said.

UK Prime Minister Keir Starmer described the incident as 'horrendous and shocking'.

"Horrendous and deeply shocking news emerging from Southport. My thoughts are with all those affected.I would like to thank the police and emergency services for their swift response.I am being kept updated as the situation develops," he said.