Serbian water polo players were attacked by a group of nationalists ahead of a match in Croatia.
The incident on February 9 occurred at a beachfront cafe in the Croatian city of Split before a regional league match between Mornar Split and Red Star Belgrade.
One Red Star player even jumped in the sea at Split in a bid to escape the attackers.
Red Star decided not to play the match and returned to Belgrade.
The team said the goalkeeper had a broken nose after being attacked by "Croatian hooligans."
"Split is not a town which will tolerate violence of any kind," Mayor Andro Krstulovic Opara said. "I condemn the attack against three Red Star players who today wanted to enjoy the Split beachfront."
Tensions are still high between Croatia and Serbia after their war in the 1990s.
Based on reporting by AP and AFP