Objects have reportedly been thrown into the Celtic dugout during the match against Rangers.
Sky Sports reports missiles were launched into the technical area in the aftermath of Cyriel Dessers' disallowed goal.
Commentator Ian Crocker said: "Sadly, there are objects being thrown into the Celtic dugout."
Footage on the broadcast then showed Celtic assistant John Kennedy in discussions with a police officer over the incident.
It came after John Beaton's decision to rule out Dessers' strike - which would have equalled the scores - for a foul in the build-up by Tom Lawrence on Tomoki Iwata.
More to follow.
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