Poland's health minister says the mayor of Gdansk has died following a stabbing attack at a charity event.
Pawel Adamowicz was rushed to hospital after being stabbed on Sunday evening.
The 53-year-old grabbed his stomach and collapsed in front of an audience while on stage with the Great Orchestra of Christmas Charity.
Doctors operated for five hours on Mr Adamowicz, who was stabbed in the heart and abdomen on Sunday by an ex-convict who rushed onto the stage with a knife.
The man shouted out the attack was an act of revenge against a political party Mr Adamowicz had belonged to.
Police said the suspect was a 27-year-old who had been recently released from prison and served a term for bank robberies.
A police spokesman, Mariusz Ciarka, said the attacker appeared to have mental health problems and gained access to the area with a media badge.
It is unclear how he acquired the credential and is under investigation.
Mr Adamowicz had been mayor of Gdansk since 1998.
He was part of the democratic opposition born in that city under the leadership of Lech Walesa during the 1980s.
As mayor, he is seen as a progressive voice and has supported LGBT rights and tolerance for minorities.
He showed solidarity with the Jewish community when the city's synagogue had its windows broken last year, strongly denouncing the vandalism.
Gdansk is one of Poland's largest cities, on the country's Baltic coast, with a population of around 570,000.