Two people were injured after pyrotechnics were set off in the Rangers section during their game with Livingston on Wednesday.
A 26-year-old woman suffered a minor leg injury and a 13-year-old boy needed treatment to his eyes as a result of smoke bombs, bangers and flares being set off in the stand.
A police officer was also hit by a coin thrown from the Rangers end during the League Cup quarter-final.
Chief inspector Neil Mitchell, the officer in charge of policing the match, said: “Taking pyrotechnics into a football stadium is not only an offence, it is extremely dangerous.
“The injuries sustained by the woman and boy caused by the devices, and the consequences, could have had been so much worse.
“Once again it is extremely disappointing and worrying that despite repeated warnings about the risk pyrotechnics bring, a small minority continue to smuggle them into matches.
“The vast majority of those who attended the match were well -behaved and enjoyed the game. However, following the actions of a small group of their fellow supporters, two people were injured.
“It is only down to luck that their injuries were minor. If this continues it can only be a matter of time before someone is injured more seriously.
“One of my officers was also struck by a coin thrown from the same group of supporters . This is also unacceptable and will not be tolerated.”
Rangers won the game 1-0, to book them a semi-final clash against Hearts, thanks to an early goal from Glen Kamara.