British police said 10 people have been hospitalized, nine with life-threatening injuries, following a mass stabbing attack on a London-bound train Saturday evening, and that counter-terrorism police are supporting the investigation.

At least nine people suffered life-threatening injuries after a mass stabbing on a London-bound train in the United Kingdom’s Cambridgeshire.

Prime Minister Keir Starmer called the incident “appalling” and said his thoughts were with the victims and their families.