Portuguese police have arrested a man over the death of an England fan in a suspected attempted robbery.
The man is reported to have been stabbed in Rossio Square, Lisbon, in the early hours of Tuesday morning.
The Foreign Office was able to confirm a man had died but said no other details would be available until his family had been informed.
"We can confirm that a British national has been killed," the Foreign Office spokeswoman said.
The man was taken to Sao Jose hospital in Lisbon where he was pronounced dead on arrival, Portuguese police said.
The death was the only incident reported after England's 4-2 victory over Croatia on Monday night.
A BBC correspondent in Lisbon said the mood in the city had seemed peaceful following the match.