An estimated £10,000 worth of damage was caused to seating in the middle lower area of the South Stand at Fir Park, just above where a Green Brigade banner was displayed.
A flare was let off in the same area before the game while two green smoke bombs were thrown into the goalmouth, one of them landing yards from Hoops goalkeeper Fraser Forster.
Celtic have described the scenes as "appalling".
Police Scotland is looking into the "significant damage" caused to seats and it counted 18 smoke bombs, three fireworks and one flare set off. No arrests were made inside Fir Park.
Celtic have launched their own investigation while the Green Brigade fans group has also condemned the vandalism and admitted it should have self-policed its section more effectively.
A Green Brigade statement read: "Firstly we do not condone the breaking of seats nor do we welcome pyrotechnics being thrown on the park. We as a group are as disappointed as any about such indefensible behaviour and regret that it happened on our watch.
"Ultimately, we should have had greater control of the bodies present within our block and our failure to do so has resulted in events which are unacceptable."
The main Celtic fans' group, the Affiliation of Registered Celtic Supporters Clubs, expressed frustration at the actions.
A statement read: "We should be discussing another devastating Celtic performance on the pitch instead we are talking about disappointments off the field."