Discriminatory chants prompted a Serie A game between Roma and Napoli to be briefly suspended on Saturday.
Referee Gianluca Rocchi made the decision in the second half after Roma fans aimed anti-territorial chants at Napoli.
Such chants are often used by supporters to deride an opposing club's city and are treated by officials in the same manner as racist chants -- which an Associated Press photographer next to the pitch also heard being aimed at Napoli defender Kalidou Koulibaly.
By that point, Rocchi had already ordered an announcement to be made over the Stadio Olimpico's public address system asking fans to stop the chants.
During the suspension, Rocchi gathered teams in the centre circle, then Roma forward Edin Dzeko encouraged fans to applaud rather than jeer the opposition.
The game resumed after a few minutes.
"Since my Italian is not good I didn't really understand what happened, but I'm against any sort of territorial discrimination," Paulo Fonseca, Roma's Portuguese coach, said.
He said incidents like these happen "in many matches all over the world," adding: "To me, it was more important to see our captain [Dzeko] talk to the fans and see that it didn't occur again."
Roma led 2-0 at the time of the suspension before going on to win 2-1.