Celtic's manager has slammed people throwing missiles at members of his staff as "idiots".
A member Ange Postecoglou's team was left needing stitches after being struck by an object.
His team came from behind to beat Rangers 2-1 at Ibrox and move six points clear at the top of the table, but the game was marred by instances of fans throwing objects onto the pitch, Football Scotland reports.
The second half was delayed after Joe Hart had to point out shards of broken glass laying in his penalty area.
Ground staff removed the debris, but minutes later Jota was targeted with a plastic tumbler and what appeared to be a coin as he prepared to take a corner.
And Postecoglou said he was at a loss as to what the individuals responsible were thinking.
Read more: Ibrox Stadium targeted in late-night vandalism spree as police arrest three men
“It is disappointing,” he said. “I thought it was a proper derby, the atmosphere was unbelievable, both teams were up for it, both teams were going for it.
“You don’t need it. I don’t know what people are trying to achieve by doing that. I thought it was a fantastic spectacle.
“Sitting here now as the winning coach that kind of taints my view of it, but I thought anybody watching that would agree it was a good game of football and you could tell there was something meaningful at the end of it by the way both sets of players went at it.
“Like I said their crowd was up for it, our 700 was up for it and couldn’t stop signing. That is what you want.”
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When asked about a member of his staff needing treatment after being struck as the benches made their way up the tunnel, Postecoglou replied: “Yeah, he was on the way in. I think he is okay, He had a couple of stitches.
“It is disappointing because this is a game that gets beamed around the world and it stands on its own. You had two teams going at it in first and second spot and you don’t need a couple of idiots spoiling it.”
A Celtic statement read: “We can confirm that a member of our backroom staff was struck by a glass bottle. He required urgent medical treatment and stitches to a head wound. The matter is now in the hands of Police Scotland.”
