WARSAW, Poland (AP) -- Flags flew at half-staff and people signed condolence books at municipal buildings across Poland and in diplomatic missions abroad on Tuesday as the nation mourned the stabbing death of the popular liberal mayor of port city Gdansk.
In Gdansk, people placed flowers and candles and signed a condolence book at the town hall, where Mayor Pawel Adamowicz had his office since he was first elected mayor in 1998.
In the capital Warsaw, Prime Minister Mateusz Morawiecki and members of his Cabinet stood for a moment of silence in Adamowicz's honor before their weekly meeting.
Meanwhile, Interior Minister Joachim Brudzinski said police have arrested three people who had called for more killings following the assassination of Adamowicz, who died Monday after being stabbed during a charity event.
Brudzinski described those arrested as internet trolls and "unbalanced."
The assailant stabbed Adamowicz three times in the heart and abdomen while on stage during a charity event Sunday evening. He then told a crowd of thousands he did it in revenge against the opposition Civic Platform party, which was in power when he was imprisoned in 2013 for bank robberies.
Adamowicz was a longtime member of Civic Platform but left it in 2015.
Officials have identified the assailant as 27-year-old Stefan W. from Gdansk who left prison in December after serving more than five years for bank robberies. Justice officials said he needed psychiatric examination and that a psychiatrist assisted at his questioning Monday.
The killing plunged the politically divided country into shock and grief and brought Poles into the streets for solemn vigils Monday night.
It also threatened to exacerbate a tense political situation in the country, with Poles bitterly divided between supporters of the ruling right-wing party Law and Justice and critics who accuse it of creating a climate of intolerance and eroding democratic standards. They have primarily focused their criticism on the party's reshaping of the judicial system and its use of public media as a political tool.
Some Poles put some of the blame for the assassination on the right-wing ruling Law and Justice party, which has often employed harsh language to denounce its critics, among them Adamowicz.
Government officials and some independent observers called for caution, noting the assailant's criminal record and suspected psychiatric problems.
Amid the recriminations, the state broadcaster, TVP, ran a report on its main evening news program Monday evening that selectively showed clips of officials with Civic Platform using harsh language against Law and Justice over the years. It left out the many examples of verbal aggression by Law and Justice officials, creating an impression that Civic Platform is solely responsible for the rising level of animosity in the country.
Adamowicz was part of the democratic opposition formed in Gdansk under the leadership of Lech Walesa during the 1980s. After leaving Civic Platform, he was re-elected to a sixth term as an independent candidate last fall.
As mayor, he was a progressive voice, promoting tolerance for LGBT people and minorities. He showed solidarity with the Jewish community when the Gdansk synagogue had its windows broken last year, strongly denouncing the vandalism. He had also advocated bringing wounded Syrian children to Gdansk for medical treatment, but the plan was blocked by the Law and Justice government.
For years, he was denounced by members of Law and Justice and some further to the right, who accused him of lacking patriotism or promoting degenerate values with his liberal views.
After his death, condolences came in from leaders from across Europe.
The Gdansk mayor was also fondly remembered in Russia, especially in its western exclave of Kaliningrad which is nestled between Poland and Lithuania. Kaliningrad residents on Monday brought flowers and candles to the Polish consulate to honor Adamowicz's memory.