London, July 30 (IANS): Two children are confirmed dead in a knife attack on Monday in Southport, Merseyside, in northwest England, according to local police.

Nine other people have been injured, six of whom are in critical condition, Chief Constable Serena Kennedy was quoted as saying by Xinhua news agency.

It is understood that the children were attending classes at the "Taylor Swift Yoga and Dance Workshop" for minors aged seven to 11 when the attacker entered. Among the injured are two adults who were intervening in the attack. "We believe that the adults who were injured were bravely trying to protect the children who were being attacked," the police said.

A 17-year-old boy from Banks in Lancashire has been arrested on suspicion of murder and attempted murder.

The motivation behind the attack remains unclear as the investigation is still in its early stages, the police said.

Police declared the stabbing a "major incident," adding that it is not being treated as terror-related at this time.

Prime Minister Keir Starmer said the attack is "truly awful" and the "whole country is deeply shocked."

The knife attack was reported at around 11:50 a.m. in a property on Hart Street, Merseyside Police said in a statement earlier on Monday.