A man is in hospital with multiple serious injuries after being attacked in street.
Police are treating Thursday night's assault on the 25-year-old in Wishaw as attempted murder.
They were unable to confirm reports that the victim had been hit with a machete.
The disturbance broke out in Lomond Drive in the North Lanarkshire town at around 11.20pm, during which the man was attacked.
A Police Scotland spokeswoman said: "He sustained multiple serious injuries and was taken by a member of the public to Wishaw General Hospital, where he is currently being treated. Hospital staff describe his condition as critical."
Detectives have launched an attempted murder probe and are thought to be following a number of lines of inquiry.
Anyone with information is being asked to contact Wishaw CID via the 101 number or Crimstoppers on 0800 555 111.
Detective Inspector John Lamb, of Wishaw CID, said: "The man was stabbed and beaten in what I would say was an extremely brutal attack.
"From our enquiries, we believe that around 8pm, earlier on Thursday evening, the injured man had been involved in a dispute with a number of other people near to an unofficial bonfire display in Pather.
"He left shortly after but returned to the area around 10.30pm when a large-scale disturbance happened near to Thornlie Primary School in Lomond Drive, Pather. He was then set upon by a small number of people in the same street.
"Officers have been carrying out door-to-door enquiries and checking CCTV in the area. So far, the response form the local community has been encouraging, however we still need people to come forward.
"After the attack, the man was taken by a passing member of the public to Wishaw General. A number of other people had also tried to help him and break up the attack.
"I believe the disturbance and subsequent attack was between two factions in the area who may or may not have known each other.
"There is no excuse for such behaviour and the level of violence used, which was undoubtedly witnessed by decent members of the community returning from bonfire night celebrations.
"I would appeal to anyone who saw the attack, or who has any information that will help police with enquiries, to come forward to police."