Banners depicting Sands, who died on hunger strike in Northern Ireland's Maze Prison in 1981, and William Wallace, were accompanied by others which read: "The terrorist or the dreamer? The savage or the brave? Depends whose vote you are trying to catch or whose face you're trying to save."
Uefa yesterday confirmed it is investigating an incident of a "non-sporting nature" at the match against AC Milan at Celtic Park, which Celtic lost 3-0.
The banners were held in the section of the ground housing self-styled "ultras" group the Green Brigade and were the second attempt in as many games to compare Flower of Scotland with The Roll of Honour, an anthem to the 10 members of the Provisional IRA and INLA who died during the hunger strikes.
Sands, who died after 66 days, was the first victim of the 1981 protest over then Prime Minister Margaret Thatcher's refusal to recognise their claims to be political prisoners. They wanted better conditions than other inmates at the Maze Prison in Northern Ireland, including being able to wear civilian clothes and mix freely with each other.
The Scottish Professional Football League confirmed it had received complaints about the banner at Saturday's Aberdeen game and has launched its own investigation.
Uefa will deal with the case on December 11, with its code stating that clubs may be subject to disciplinary measures if supporters are found to have used "gestures, words, objects or any other means to transmit any message that is not fit for a sports event, particularly messages that are of a political, ideological, religious, offensive or provocative nature".
Celtic were previously fined over a banner displayed during a Europa League tie against Udinese in 2011, while a penalty was also imposed for fans setting off fireworks during a Champions League qualifier this season.
The club have previously warned supporters in section 111 of the stadium, known to house the Green Brigade, over their conduct. Chief executive Peter Lawwell yesterday accused the Green Brigade of showing "clear disrespect".
Celtic also said "that any individual or group identified as being involved in any form of political display at a match involving Celtic will be banned immediately from attending matches involving the club".
Mr Lawwell said: "There have now been a number of UEFA charges made against the club during the last three years, relating to behaviour, displays and pyrotechnics. It cannot go on any further.
"It is the reputation of Celtic, our great club and our great fans which is damaged, while others carry on indulging in such behaviour.
"Our supporters do not want this any more. We are a non-political organisation, a top football club in fantastic shape, aiming to play its part as a major football club on the European stage.
In a statement, the Green Brigade said: "Given that it is Celtic fans who are filling up prison cells and court rooms because of the Football Act and the manner in which it criminalises legitimate expressions of political opinions, this display could not have been more relevant in the current context."