Police on Monday arrested a man on suspicion of murder following a series of stabbings in Birmingham, Britain's second city, that left one person dead and three critically injured.
The 27-year-old suspect was held in a pre-dawn raid in the Selly Oak area following the apparently random attacks around the city centre in the early hours of Sunday morning.
The man killed was named as Jacob Billington, 23, who had been on a night out with friends when he was stabbed.
In a statement, his family said they were devastated that "the light of our life" had gone, adding: "He was a funny, caring and wonderful person who was loved by every single person he met."
Seven people were injured, including one of Billington's friends, also 23, who is in a critical condition in hospital.
Another man aged 30 and a 22-year-old woman, attacked in different parts of the city centre, are also critically ill in hospital, police said.
The murder suspect "remains in custody on suspicion of murder and seven counts of attempted murder," they said, adding that three other people were arrested at the same address on suspicion of assisting him.
The attack occurred at four separate locations in the busy city centre between 12:30 and 2:30 am on Sunday.
One of the areas was in the heart of Birmingham's Gay Village but officers ruled out a hate crime. They also rejected any links to gang violence or terrorism.
"We are working hard to discover what led to the apparently random attacks," said police chief Steve Graham.
"We have no suggestion that the motive was either racial, homophobic or gang-related."
Britain has been on high alert after two mass stabbings in London in the last year that saw armed officers shoot dead both perpetrators -- convicted Islamic extremists who had been released early from prison.
In June, a man was charged with murder after three people were stabbed to death in a park in Reading, west of London, in an attack under investigation by counter-terrorism police.
Six people, including a police officer, were then injured at a hotel housing asylum seekers in the Scottish city of Glasgow. Armed police shot dead the suspected attacker.
Stabbings in England and Wales increased six percent in the year to the end of March, according to the Office for National Statistics.
Birmingham is one of Britain's most ethnically diverse cities with a population of more than one million, and has had an explosive recent history of gang violence.
Prime Minister Boris Johnson and Home Secretary Priti Patel both sent condolences to the victims and thanked the emergency services, who declared a "major incident" in response to the attacks.