A 21-year-old man is in a critical condition in hospital after a fight involving about 20 men and women armed with baseball bats and shovels.
The disturbance happened at about 0230 GMT on Boxing Day on Hogganfield Street in the Provanmill area of Glasgow.
Police believe the fight was between rival gangs in the area.
Strathclyde Police are treating the incident as attempted murder. Officers said they received numerous calls about the fight and appealed for information.
Det Sgt John Semple said: "We believe that the fight was between rival gangs in the area and involved up to 20 people, both men and women, fighting with baseball bats and shovels.
"We received numerous calls about the disturbance so there are plenty of people out there who will have information as to who was there, who was responsible and can give at least some details as to what actually happened."