Police Scotland are investigating after a glass bottle was thrown onto the pitch during this afternoon's Old Firm clash.
The start of the second half was delayed at Ibrox after the missile was launched into Celtic 'keeper Joe Hart's goalmouth from a stand housing Rangers fans.
Broken glass could be seen in chunks on the playing surface, with Hart demanding the shards were cleared off the park before the game could go ahead.
Several members of the Ibrox ground staff raced onto the pitch in a bid to make the 18-yard box safe again before the second half could kick off.
And now cops have confirmed they have launched a probe into the incident, with enquiries ongoing to establish exactly what happened.
Kick-off for the second period was delayed by three minutes as Rangers tried to get back into the game, having gone 2-1 behind shortly before half-time thanks to Cameron Carter-Vickers' well-taken goal.
Sky Sports co-commentator Ally McCoist branded it an act of "gross stupidity" while colleague Andy Walker also hit out at the missile that came from the home end.
Walker believes the moment of madness is damaging the reputation of the world famous derby.
The former Celtic striker said: "We're trying to sell this game around the world. Shameful anyone would throw anything on to the pitch, let alone a broken bottle.
Dismayed Rangers hero McCoist added: "You think nothing would surprise you any more but dearie me. Gross stupidity."
After the game, Gers boss Giovanni van Bronckhorst blasted the culprit for delaying the restart and making the pitch unsafe for players.
A Police Scotland spokesperson said: "We are aware of a glass bottle being thrown on the pitch at Ibrox Stadium, Glasgow during the Rangers v Celtic match on Sunday, 3 April, 2022.
"Enquiries are currently ongoing to establish the full circumstances."
Celtic extended their lead at the top of the Premiership to six points with just six games to go after today's derby victory.
The hosts took the lead after just three minutes with Aaron Ramsey finishing coolly to give Rangers to perfect start.
But just four minutes later, Tom Rogic levelled matters for the Hoops, scoring from close range after Allan McGregor saved a shot from Reo Hatate.
And Sky Sports man-of-the-match Carter-Vickers would prove to be the matchwinner when he struck a decisive blow after the Light Blues failed to deal with a Celtic free kick.
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