Large scale football violence returned to Glasgow's streets last weekend when 100 Partick Thistle and Airdrie fans clashed on Arlington Street.
Police say that a man was left seriously injured after brawling erupted between dozens of the fans, leaving the streets littered with bricks, bottles and blood.
The groups met at around 14.20 on the afternoon before the match between the two Division One sides.
Strathclyde Police said they are trying to identify those involved in the fight and establish the circumstances surrounding it.
Sergeant Marian Maclean said: "Officers are checking CCTV, speaking to local businesses and are carrying out door-to-door inquiries in the area.
"We would specifically like to hear from any eye witnesses, including those who may have taken any mobile phone or digital camera images of the disturbance, or owners of business premises with CCTV which may have captured images."
A Partick Thistle spokeswoman said: "We have not been officially notified of the incident but obviously we don't condone fans doing anything which could bring the club into disrepute."
A spokeswoman for Airdrie said the fight had not been reported to them.