Ukrainian president warns of attacks ahead of Independence Day

Russian forces pressed on with their offensive across several Ukrainian regions on August 21, while President Volodymyr Zelenskyy warned of the potential for more serious attacks ahead of Ukraine's 31st anniversary of independence from Soviet rule.

Artillery shells rained down on Nikopol, a city near Zaporizhzhia - Europe's biggest nuclear plant, while missiles struck near the Black Sea port of Odesa over the weekend, Reuters reported on August 22.

Zelenskyy has called for vigilance, saying Moscow could try "something particularly ugly" ahead of Wednesday, which marks Ukraine's Independence Day and also half a year since Russia invaded Ukraine on February 24.

Zelenskyy said he had discussed "all the threats" with French President Emmanuel Macron and word had also been sent to other leaders including Turkish President Tayyip Erdogan and U.N. Secretary-General Antonio Guterres.

"All of Ukraine's partners have been informed about what the terrorist state can prepare for this week," Zelenskyy said in his nightly video address, referring to Russia.

He also said if Russia went ahead with plans to try captured Ukrainian defenders in Mariupol, then it would have violated international rules and cut itself off from negotiations.

"If this despicable show trial were to go ahead ... this would be the line beyond which negotiations are no longer possible," he said. "There will be no more conversations. Our state has said everything."

The Financial Times, in an article published on August 21, quoted Gennady Gatilov, Moscow's ambassador to the United Nations in Geneva, as saying Erdogan had tried to facilitate dialogue.

But he dismissed speculation about talks between Zelenskiy and Russian President Vladimir Putin, saying there "was not any practical platform for having this meeting", the report said.

In Russia, authorities are investigating a suspected car bomb attack outside Moscow that killed the daughter of Alexander Dugin, an ultra-nationalist Russian ideologue who advocates Russia absorbing Ukraine.

While investigators said they were considering "all versions" when it came to establishing who was responsible, the Russian Foreign Ministry speculated there could be a link to Ukraine, something a Zelenskiy adviser dismissed.

"Ukraine, of course, had nothing to do with this because we are not a criminal state, like the Russian Federation, and moreover we are not a terrorist state," Mykhailo Podolyak said on Ukrainian TV.