A mayor in Poland was stabbed while he was on stage at a charity event in what was described as an act of "inexcusable barbarity".
Pawel Adamowicz, mayor of Gdansk, was attacked in front of hundreds of spectators of the city at an event for the benefit of the Grand Orchestra of Christmas charity.
Interior Minister Joachim Brudzinski said the 53-year-old man was taken to hospital in a very serious condition.
A Maltese on stage as mayor attacked (the moment of impact was removed from the video)
He added in a tweet that an act of "inexcusable barbarity" had occurred.
According to the Polish television channel TVN, the suspect shouted on the podium and claimed to have been improperly imprisoned by the previous government.
The Polish police later confirmed on Twitter that she held a suspect as a result of the incident.
The mayor of Gdansk would be in a very serious state
Several key politicians have posted messages of support
The President of the European Council, Donald Tusk, tweeted a message of support to Mr Adamowicz in which he said: "Let's all pray for Mayor Adamowicz, Pawel, we are with you".
Polish Prime Minister Mateusz Morawiecki tweeted: "The attack on the life and health of Pawel Adamowicz is worthy of the highest sentence."
Moments before the incident, Mr. Adamowicz posted a picture of the scene view on his Instagram account.
The photo showed a crowd of spectators wielding bright white lights during the Lights To Heaven event, which had raised funds for the purchase of medical equipment for the Polish health system.
Mr. Adamowicz was attacked in front of hundreds of spectators
This politician has been mayor of Gdansk for more than 20 years and is part of the democratic opposition born in the city during the reign of Lech Walsea in the 1980s.
He has been seen as a progressive voice in the country, supporting LGBT rights and tolerance of minority groups.
The Polish President, Andrzej Duda, said that despite their political differences, he was "unconditionally with him and his relatives, just like, I hope, all our compatriots".
He said he was informed that "the doctors have managed to revive the heart of the mayor seriously injured, Mayor Pawel Adamowicz, and that there is hope, but that his condition is very difficult."