WARSAW, Poland (AP) — Poland's interior ministry says police have arrested three people calling for more killings following the assassination of the mayor of Gdansk.

Joachim Brudzinski said Tuesday on Twitter that police arrested the three on Monday, the day Pawel Adamowicz died after being stabbed while on stage during a charity event.

He described those arrested as internet trolls and "unbalanced."

It wasn't clear whose murder they were calling for.

Adamowicz was a liberal six-term mayor who was stabbed Sunday evening by an ex-convict.

The assailant stabbed Adamowicz three times in the heart and abdomen and then told a crowd of thousands he did it in revenge against Civic Platform, under whom he was imprisoned for bank robberies.

Adamowicz was a longtime member of the party but left it in 2015.