Violence and disorder has broken out in Glasgow city centre ahead of the Scottish League Cup final between Celtic and Rangers at Hampden Park.
Police said they have dealt with a number of incidents including missiles being thrown and windows smashed.
Videos on social media show large groups of football fans walking near Glasgow Central train station, followed by police officers, before running down Argyll Street and letting off flares near shoppers.
Officers have been authorised to use stop and search powers, including removing items being used to conceal identity.