Police worked to piece together details of a knife and van attack that killed two 19-year-old students and another man in the English city of Nottingham, as friends and family remembered the two younger victims as talented athletes with a passion for life.

Nottingham University students Barnaby Webber and Grace Kumar were stabbed to death in a street near student housing before dawn on Tuesday.

Police say a 31-year-old suspect also killed a man in his 60s more than 1.6km away, stole his van and ran down a group of pedestrians. Three people were hurt, one critically, in the hit-and-run.

The slain owner of the van was Ian Coates, a school caretaker. His employer said he was a “beloved and respected” staff member at a Nottingham primary school.

Police subdued the suspect with a stun gun nearby and detained him on suspicion of murder. Police said they believe the attacker acted alone and were working with counterterrorism officers to try to establish a motive. The attack has not been labelled terrorism by the authorities, and police are investigating issues including the suspect’s mental health.

The BBC and other UK media reported that the suspect, whose name has not been released, is originally from West Africa and has lived legally in Britain for many years and did not have a criminal record.

The rampage unfolded over about 90 minutes across a large swath of Nottingham, a university city of about 350,000 some 175km north of London.

A Nottingham University graduation ball scheduled for Tuesday evening was cancelled, with many students gathering instead to light candles for the victims during a vigil at St Peter’s Church.

Webber’s parents and brother said he was “a beautiful, brilliant, bright young man, with everything in life to look forward to”.

“A talented and passionate cricketer, who was over the moon to have made selection to his university cricket team,” the family, from Taunton in southwest England, said in a statement.

“Complete devastation is not enough to describe our pain and loss at the senseless murder of our son.”

Kumar also played cricket and had played field hockey for England youth teams. Woodford Wells Cricket Club near London said she was “a fiercely competitive, talented and dedicated cricketer and hockey player” who was “fun, friendly and brilliant”.

- Jill Lawless, AP