A man has been stabbed and at least 10 others injured by a lone attacker in Coventry town centre.
A 33-year-old man has been arrested, while a man in his 20s is in a stable condition in hospital after the attack in Bedworth, Warwickshire Police said.
The other victims suffered minor injuries and are assisting officers with the investigation.
The force said it believes the suspect, from Bedworth, walked along Coventry Road and Gilbert Close, where he assaulted at least 10 people just before 8am.
Detective Sergeant Rich Simpkins described it as a "nasty incident" and appealed for anyone else injured to come forward.
He said: "This was a nasty incident which has left a number of people with injuries and I know this will cause the community great concern.
"The public can expect to see a heightened police presence in and around Bedworth town centre to provide reassurance while our officers continue to conduct their enquiries.
"We have a man in custody and are not looking for any further suspects in connection with this incident.
"We know that a number of people were in the area at around the time of the incident and that there may be more members of the public who may have been approached or assaulted by the suspect.
"If you were approached by the suspect or may have witnessed the incident, I would urge you to get in touch.
"Any information you may have could really assist with our investigation."
Anyone with information, or with dashcam or phone footage of the Coventry Road and Gilbert Close area between 7.45am and 8.05am should call 101 quoting incident number 91 of 23 April. Details can also be provided anonymously to independent charity Crimestoppers on 0800 555 111.