Polish mayor Pawel Adamowicz has died in hospital after being stabbed on stage at a charity event.
Mr Adamowicz, the mayor of Gdansk, was attacked in front of hundreds of people in the city on Sunday during an event in aid of the Great Orchestra of Christmas Charity.
He underwent five hours of surgery for wounds to his heart and abdomen, as locals queued to donate blood, but health minister Lukasz Szumowski told reporters on Monday: “We couldn’t win.
“It was not possible to overcome everything that had happened to him. May he rest in peace.”
Police arrested a 27-year-old with a criminal record on suspicion of attempted murder and he remains in custody.
Investigators said he appeared to have mental health problems and gained access to the stage with a media badge.
According to Polish broadcaster TVN, he shouted from the stage and claimed that he had been wrongly imprisoned by the previous government.
The suspect – who authorities said was previously convicted of involvement in bank robberies and served a five-and-a-half-year prison term – will be subjected to a psychiatric examination.
Following news of his death, EU Council President Donald Tusk tweeted: “Pawel Adamowicz, Mayor of Gdansk, a man of solidarity and freedom, a European, my good friend, has been murdered. May he rest in peace.”
On Sunday, Polish interior minister Joachim Brudzinski had condemned the attack on the 53-year-old mayor as an act of “inexcusable barbarity”.
Moments before the incident, Mr Adamowicz posted a photo of the view from the stage to his Instagram account.
The picture showed audience members holding up bright white lights during the Lights To Heaven event, which raised money for medical equipment for the Polish healthcare system.
The politician had been mayor of Gdansk for more than 20 years and was part of the democratic opposition which started in the city under Lech Walesa in the 1980s.
He had been seen as a progressive voice in the country, supporting LGBT rights and tolerance for minority groups.
Anti-violence rallies are being planned nationwide in response to the attack.