Two children have died and nine others are injured after a stabbing in the English town of Southport, north of Liverpool.
All of the nine children who were injured were stabbed and six are in a critical condition.
Two adults are also in a critical condition following the attack just before midday.
Merseyside Police Chief Constable Serena Kennedy said: "We believe that the adults who were injured were bravely trying to protect the children who were being attacked."
A 17-year-old boy, who is originally from Cardiff in Wales, has been arrested on suspicion of murder and attempted murder.
Taoiseach Simon Harris said he is "absolutely horrified at the devastating attack".
"The loss of children is an unbearable atrocity".
On X (Twitter) he said he was sending the support of the Irish people to British Prime Minister Keir Starmer, the families and communities.
Absolutely horrified at the devastating attack in Southport. A terrible tragedy. The loss of children is an unbearable atrocity.
Sending the support of the Irish people to @Keir_Starmer, the families and communities.— Simon Harris TD (@SimonHarrisTD) July 29, 2024
Police were called to reports of a knife attack at an address in Southport at 11:47am this morning.
Chief Constable Kennedy said that when officers arrived they were "shocked to find" several children had been "subjected to a ferocious attack and had suffered serious injuries".
She added: "It is understood that the children were attending a Taylor Swift event at a dance school when the offender, armed with a knife, walked into the premises and started to attack the children inside."
Police in Southport, Merseyside in England after a number of people were injured in a stabbing, 29-7-24. Image: PA Images / AlamyPolice said the suspect's motive is unclear at this early stage but the investigation is not being treated as terror-related.
It is understood the stabbings took place at a community centre called Hart Space, often used for mother and baby classes.
A poster shows a 'Taylor Swift Yoga and Dance Workshop' aimed at children aged between seven and 11 was taking place at the centre at the time of the attack.
Specialist officers are supporting the families of the children who were killed and those were injured, Chief Constable Kennedy said.
Forensic officers in Southport, Merseyside in England after a number of people were injured in a stabbing, 29-7-24. Image: PA Images / AlamyMerseyside Police declared a "major incident" after the stabbings and armed police seized a knife after arresting the teenage suspect.
The force then urged the public to avoid the area - as one local businessman described the scene as like a "horror movie" and said "mothers were screaming" in the aftermath.
Victims have been taken to a number of local hospitals.
British Prime Minister Keir Starmer said the attack was "horrendous and deeply shocking".
He thanked the police and the emergency services, adding he was being kept updated as the situation developed and his thoughts were with those affected.
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.— Keir Starmer (@Keir_Starmer) July 29, 2024
The UK Home Secretary Yvette Cooper wrote on X (Twitter): "The news from Southport is truly devastating. My heart goes out to all the families affected by this horrific incident & to the whole community."
Reporting by: IRN
