(LONDON) — A 32-year-old man has been arrested on suspicion of attempted murder following a knife attack on a train traveling to London on Saturday evening. The incident, described by the Prime Minister as an "appalling incident," left several people injured. British Transport Police (BTP) reported that two individuals were initially arrested after the attack. However, a 35-year-old man taken into custody was released on Sunday after police determined he was not involved. The most seriously injured victim is a staff member of the London North Eastern Railway (LNER). He was stabbed while trying to intervene and protect other passengers. Deputy Chief Constable Stuart Cundy commended the railway employee for his bravery, stating, "Having viewed the CCTV from the train, the actions of the member of rail staff were nothing short of heroic and undoubtedly saved people’s lives." As of Sunday evening, the LNER staff member remained hospitalized in critical condition. Five other victims were treated for stab wounds and later released. In total, ten people were transported to hospitals, with an additional alleged victim seeking treatment independently later that night. Initially, nine individuals were reported to have life-threatening injuries. The BTP began receiving reports of the stabbings at 7:42 p.m. on Saturday. The train, which was en route from Doncaster to London’s King’s Cross station, made an unscheduled stop at Huntingdon, approximately 70 miles north of London. Armed officers boarded the train and arrested the suspect, whose identity has not been disclosed. A knife was recovered at the scene. The suspect is believed to be from Peterborough, located about 74 miles from London. Investigators suspect he boarded the train at the Peterborough station. Cundy noted that specialist detectives are examining the suspect's background and the events leading up to the attack. “This was a horrific attack that has had a wide impact,” Cundy said. He expressed his thoughts for the injured and their families, particularly for the railway staff member. The UK’s Counter Terrorism Policing is assisting in the investigation to determine the full circumstances and motivation behind the incident. Superintendent John Loveless stated, "At this stage, there is nothing to suggest this is a terrorist incident," and emphasized that it is too early to speculate on the causes. Loveless also mentioned that the suspect was apprehended within eight minutes of the first emergency call. British Prime Minister Keir Starmer expressed his concern, stating, "The appalling incident on a train near Huntingdon is deeply concerning. My thoughts are with all those affected, and my thanks go to the emergency services for their response." Home Secretary Shabana Mahmood confirmed she was receiving regular updates on the investigation and urged the public to refrain from speculation. King Charles III expressed his shock and sympathy in a statement, saying, "My wife and I were truly appalled and shocked to hear of the dreadful knife attack that took place on board a train in Cambridgeshire last night. Our deepest sympathy and thoughts are with all those affected, and their loved ones." The investigation is ongoing as authorities work to gather more information about the incident and the suspect's motives.