Rangers fans are suspected of letting off fireworks outside a hotel housing the Celtic team last night.
Loud bangs were heard late into the night at the Dakota Hotel on the outskirts of Glasgow.
The tactic has become commonplace in Europe, with unwanted noise used to rattle opposition teams, the Daily Record reports.
The Hoops would have been looking forward to a quiet night at the hotel based at Eurocentral ahead of today's Old Firm clash.
But it appears they will have been disappointed by the unwanted disturbance ahead of the showdown.
Several loud bangs could be heard in a short video clip with supporters letting off the pyro within distance of the hotel.
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Celtic supporters will be hoping the brief commotion will have little impact on the action for Ange Postecoglou's side at Ibrox.
The league leaders know a win will see them six points clear at the top of the table and in a commanding position with only six league games to follow.
The pair will meet again at Celtic Park in the final fixture after the split.
