The popular veteran mayor of the Polish city of Gdansk, Pawel Adamowicz, was stabbed on Sunday evening by a man who burst onto an open-air stage at a national charity event, police said.
Television footage showed the man screaming that "Adamowicz is dead" because his former party, Civic Platform, which held power from 2007 to 2015, had purportedly tortured him when he was in prison.
Adamowicz, 53, was attending the finale of the annual Great Orchestra of Christmas charity event, in which volunteers collects millions of euros for medical equipment for hospitals.
Local media quoted hospital staff as saying Adamowicz's condition was very serious and he was being operated on.
Adamowicz has been mayor of Gdansk since 1998. In the 2018 regional election, he won 65 percent of votes.