Police have arrested five men believed to have played a part in the violence that erupted after last year's UEFA Cup football 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 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.
Police say today's arrests will be the first in a series of coordinated raids.