Two 19-year-olds and man in his 50s were killed in the Nottingham attacks, police said.
The students were stabbed to death in Ilkeston Road at about 4am on Tuesday while the other man’s body was found in Magdala Road.
One of the students was named as Barnaby Webber on Tuesday evening.
At a press conference on Tuesday afternoon, Nottinghamshire Police chief constable Kate Meynell said it was believed the older man’s van had been stolen and was driven at three people in Milton Street.
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One man remains in hospital in a critical condition while two others suffered minor injuries following that incident.
A 31-year-old man remains in police custody after being arrested on suspicion of murder.
The University of Nottingham said two of the victims were students there.
A statement read: “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.
“We are shocked and devastated by the news and our thoughts are with those affected, their families and friends. We know this is likely to cause distress for staff and students in our community.”
A suspect driving a van tried to run over three people near the city’s Theatre Royal.
Major roads in the city centre are set to remain closed as the police investigation continues.
Ms Meynell said: “This is a tragic series of events which has led to the lives of three innocent people being taken and left another member of the public in a critical condition in hospital.
“My thoughts are with all the families affected by this shocking incident and we will be working extremely hard to understand exactly what has happened.
“We are at the early stages of the investigation and need to determine the motives behind these attacks, and will keep the public updated as soon as we are able to say more.
“We are keeping an open mind as we investigate the circumstances surrounding these incidents and are working alongside Counter Terrorism Policing to establish the facts – as we would normally do in these types of circumstances.
“We do have a man in custody who has been arrested on suspicion of murder. Currently, we do not believe there is anyone else involved in this incident.
“It is safe to go into the city centre but there are a number of streets that will remain closed including Ilkeston Road, Magdala Street, Milton Street and Maple Street. This is so officers can gather evidence in order to understand what has happened.”
Witnesses have given harrowing accounts of victims being stabbed and run over by a van.
One witness told the BBC he saw a young man and young woman being stabbed in Ilkeston Road, close to the junction with Bright Street.
The man, who did not give his name, said he heard “awful, blood-curdling screams”.
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. It was repeated stabbing – four or five times. 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. The attacker then just walked off up Ilkeston Road towards town, as calm as anything.”
Police activity continued in various locations along Ilkeston Road on Tuesday, with parts of the street cordoned off and armed officers deployed, some of whom came from Derbyshire Police and South Yorkshire Police, while others appeared to be specialist counter-terrorism firearms officers.
Two women were taken away from one commercial property in a police van shortly before 1pm.
A terraced property was also under police guard, with staff at a neighbouring hairdresser saying it had been raided last year.
Witnesses in Bentinck Road described the suspect struggling as officers dragged him out of a white van.
Student Demi Ojolow, who lives in the road, said: “I just saw the police shouting at him to get out of the car and get on the floor.
“And they dragged him out of the car and he just fell on the floor. He was still pretty wrestling at the point. They dragged him away and that was about it.”
Damage could be seen to the bonnet and windscreen of the van which was left at the scene.
Another Bentinck Road resident, Dimitrious Lawani, arrived at the scene just as the man was being pulled out of the van.
He said: “There’s two of them pulling him and two behind pointing at him – I think those were Tasers.”
The witness said they shouted: “Get down, get out, stop fighting.”
Lynn Haggitt told Channel 4 News she saw two people who were hit by a van.
“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 he went ... speeded up Parliament Street with the police cars following him,” Ms Haggitt added.
Prime minister Rishi Sunak thanked the emergency services for their response to the “shocking incident”, adding: “My thoughts are with those injured, and the family and loved ones of those who have lost their lives.” – PA