Two 19-year-old students and a man in his 50s were stabbed to death, and a further three people injured when a stolen van was driven into them, in an early morning rampage across Nottingham. A 31-year-old man has been arrested on suspicion of murder. Counter-terror police were helping officers with their investigation but Nottinghamshire police insisted they were keeping an “open mind” about the motive. The two students at Nottingham University were found unresponsive on Ilkeston Road, north-west of the city’s centre, at 4am on Tuesday. One of them was named locally as Barnaby Webber. Detectives believe the suspect then stole a white van, whose driver was later found stabbed to death on Magdala Road, two miles from where the teenagers were found. The van was then driven into people standing at a bus stop near Nottingham’s Theatre Royal at approximately 5.30am, leaving one man in critical condition and two others suffering minor injuries, police said. Officers said they were not looking for anyone else in connection with the attacks and, during the hours afterwards, armed police staged a series of raids across the east Midlands city. The second student was named in media reports as Grace Kumar, a hockey player with England U18s. Nottingham university said the two teenagers were their students: “It is with great sadness that we confirm the sudden and unexpected death of two of our students following a major incident in Nottingham city centre overnight.” The Student Union’s graduation ball – due to take place on Tuesday evening – was abandoned. Counter-terrorism police are assisting the investigation as detectives tried to understand what triggered the horrifying events, but with Nottinghamshire police still leading the investigation. Police are trying to locate any phones or computers the suspect used in the hope they can shed some light on what happened. A man who did not give his name told the BBC he had witnessed the two students being attacked with a knife on Ilkeston Road, at about 4am. He reported hearing screams and saw a man “dressed all in black with a hood and rucksack grappling with some people”. He told the broadcaster: “She was screaming: ‘Help!’ I just wish I’d shouted something out of the window to unnerve the assailant. I saw him stab the lad first and then the woman. The lad collapsed in the middle of the road. “The girl stumbled towards a house and didn’t move. The next minute she had disappeared down the side of a house, and that’s where they found her. I’d say it all happened within five or six minutes.” David Mellen, leader of the local council, told BBC Radio Nottingham that those struck by the van were “waiting at a bus stop early in the morning”. Around one mile from the scene of collision, a white van was later visible with dents to the bonnet and damage to its window, and under police guard. Lynn Haggitt, a witness, told Channel 4 News she saw a van hitting two people in Nottingham. “At half past five I saw a van pull up at the side of me,” she said. “It was white, all white. There was a police car behind it coming up slowly, no flashing lights. The man in the driver’s seat looked in his mirror and saw the police car behind him.” She said the white van then drove up to “the corner of the street and went into two people”. “The lady ended up on the kerb, and then he backed up the white van and speeded up Parliament Street with the police cars following him,” she added. Petra Gyuricska and her husband, Miklos Toldi, said they were among the first to discover the body of the man on Magdala Road at 5.30am. They were headed to Gyuricska’s workplace when they saw the man lying on his side outside Magdala tennis club. She said: “I was just leaving for work … my husband gave me a lift, and then we were leaving and we saw the body lying … on the floor, and then we saw the blood and I just told my husband to stop. I tried to call 999 but I couldn’t get connection. Someone else came as well – [in] another car – and he called.” Gyuricska said she believed the man was dead by the time they found him. She said: “We stayed … first a police car came, and then another two police cars came, and then an ambulance came. The police, they started CPR but it was too late. I mean, you could just see.” Police say the van was stopped on Maples Street where a man was Tasered and arrested by officers on suspicion of murder. Dimitrious Lawani, a witness to the arrest, said two officers were pulling a man with Tasers pointed at him, and said he heard shouts of: “Get down, get out, stop fighting.” Nottinghamshire’s chief constable, Kate Meynell, said the attacks were “shocking and tragic” and said the city centre was safe to visit: “We are still in the early stages of the investigation and need to determine the motives behind these attacks. “We are keeping an ‘open mind’ and are working alongside Counter Terrorism Policing to establish the facts.” Bishops Hull cricket club paid tribute to Webber, describing him as a “dear friend” who was a “key part” of the club. Rishi Sunak, the prime minister, said: “I am being kept updated on developments. The police must be given the time to undertake their work. My thoughts are with those injured, and the family and loved ones of those who have lost their lives.” Nottingham’s three Labour MPs, Nadia Whittome, Lilian Greenwood and Alex Norris, said they were “shaken” by the events in the city. French president Emmanuel Macron said his country “shares the grief” with Britain and “stands by their side”. The UK’s terrorist threat level for the mainland is at substantial, meaning an attack is likely.