Police have arrested five men believed to have played a part in the violence that erupted after last year's UEFA Cup final in Manchester.
The men, aged 21, 24, 27, 34 and 36, were held on suspicion of violent disorder following dawn raids at their homes in the Glasgow area on Monday by Manchester and Strathclyde police.
Rangers fans battled with riot police in Manchester after the Scottish club lost to Russia's Zenit St Petersburg in last May's final.
One Russian fan was stabbed, 15 police officers were injured and there were more than 40 arrests after street fighting broke out in the city centre.
Police estimated around 150,000 Rangers fans travelled down from Scotland for the match and officers sifted through hours of closed circuit TV footage to try and identify those suspected of being involved in the rioting.
In January, detectives released pictures of 49 people they had identified as suspects.
"The appalling events of 14 May 2008 have not been forgotten by GMP or the people of Manchester," said Detective Superintendent Geoff Wessell.
"The operation to bring those responsible to justice has been large and complex, but we have to remember that we were dealing with wanton violence on a large scale.
"Trouble of that magnitude takes time to investigate properly and it cannot be allowed to go unpunished."
Police said Monday's arrests would be the first in a series of coordinated raids.comments