"Officers are following a positive line of enquiry."
Wednesday 3 April 2019 17:02, UK
Police Scotland say they are treating the stabbing of a 47-year-old man following the Glasgow derby as attempted murder.
Three people were stabbed in a brawl, believed to be between Celtic and Rangers fans, on Blackfriars Street, Glasgow at around 5pm on Sunday.
One person is in a critical condition in hospital after sustaining serious injuries during the altercation, which is believed to have involved around 15 people.
On Wednesday, DI Peter Crombie of Police Scotland said: "We are doing everything we can and are particularly looking for mobile-phone footage of the incident as it could be the crucial piece in this investigation."
DI Crombie explained on Tuesday how police are treating the attack as attempted murder.
"We're currently going through CCTV and speaking to those who were in the area at the time, trying to establish exactly what happened.
"We are treating the attack on the 47-year-old man as attempted murder, and the attacks on the 29 and 30-year-old men as serious assaults.
"There may have been more people injured in this incident who did not seek medical treatment and I would appeal for them to come forward and speak to us.
"We also know there were a number of people in the area who may have got caught up in this incident or stopped to see what was going on. I would ask these people to check back and see if they have any mobile-phone footage or images that can help us.
"Also, if you were driving in the area you may have dash-cam footage that can help, either prior to the incident taking place or in the aftermath.
"I would ask anyone with any information about this incident, or has any footage, to please contact the police."
Celtic hosted Rangers at Celtic Park earlier on Sunday, winning the game 2-1 to take a big step towards their eighth successive Scottish Premiership title.
