Ukrainian President Volodymyr Zelenskyy has warned Russia against trying his country’s soldiers on the occasion of Ukraine’s Independence Day. “That will be the limit from which negotiations are no longer possible,” said Zelenskyj in his evening video speech on Sunday.

He cited media reports that a Russian public trial for militants captured during the siege of the Ukrainian port city of Mariupol could coincide with Wednesday’s Independence Day. There are reports of corresponding preparations by Russia.

“If this despicable court takes place, if our people are put in this position in violation of all agreements, all international rules, there will be abuse,” Selensky warned.

The Ukrainian President had previously warned of increased Russian attacks around Independence Day. “Russia could do something particularly disgusting and violent in the coming week,” said Zelenskyy on Saturday evening. According to the Interfax-Ukraine news agency, Zelenskyy’s adviser Mykhailo Podoljak added that the government is expecting increased attacks on Kyiv and other cities around the national holiday.

As a precaution, all public gatherings are prohibited in the capital Kyiv from Monday to Thursday. A curfew was even imposed in the second largest city of Kharkiv.