Football fans attending the upcoming East Anglian derby are being urged to "keep the passion on the pitch" by police.
Ipswich Town take on Norwich City at home in Portman Road on Sunday, with about 2,000 Norwich fans expected to be travelling down.
The match will be the first time the clubs have faced each other since last April because of Town's spell in the Premier League last season.
Ch Insp Matt Breeze of Suffolk Police said there would be 400 officers working the match and the force would take action against those offending.
"It's a very passionate day without a doubt," he said.