Counter-terrorism police have joined the investigation into a mass stabbing on a train that left nine people suffering with life-threatening injuries. A man with a large knife is believed to have been shot with a Taser by police after going on a bloody rampage on a high-speed train after it left Peterborough station in Cambridgeshire.

Police are investigating whether a man accused of stabbing 10 people on a train is linked to an attack on a 14-year-old boy and to two reports of a knifeman at a barbers' shop.

An LNER staff member is in a critical but stable condition in hospital following the stabbings on the high-speed service, while four other people remain in hospital.