A 27-year-old England football fan has died after being stabbed by a Croatian supporter in central Lisbon, according to the Portuguese news agency Lusa.
A Croat has reportedly been arrested over the incident.
The English man was reportedly killed in the Rossio square at around 4am after England's 4-2 win over Croatia on Monday night.
The man was taken to Sao Jose Hospital where he was declared dead.
Neither the dead man nor the Croat were identified.
The stabbing was the only violent incident reported after the game between England and Croatia.
England supporters have regularly gathered in Rossio square before and after matches.
On Monday, dozens of Croatia fans joined them in peaceful celebrations, though the Croats were largely outnumbered
It was a pickpocket - I saw one of them being pulled off the metro with some force by the cops, and given a good kicking on the way to the stadium. Once again, nothing to do with football, most unfortunate