A Russian-Belarusian rock band that denounces Moscow's Ukraine invasion returned to the stage this week, voicing defiance after being detained in Thailand in January and threatened with deportation to Russia.

The band, Bi-2, formed in the 1980s in Belarus when it was part of the Soviet Union, left Russia in protest over the offensive and has been touring ever since in countries with large Russian-speaking communities.

Ahead of a concert in Vilnius on Thursday, band members met with exiled Belarusian opposition leader Svetlana Tikhanovskaya and supporters of late Kremlin critic Alexei Navalny who died in an Arctic prison last month.

"We have become hostages to Russian history," Egor Bortnik, one of the well-known band's two founders, told AFP ahead of another concert in Warsaw on Saturday.

But 51-year-old Bortnik, who is better known by his stage name "Lyova", said he was "not against the war".

"On the contrary, I'm for the war. I just want Ukraine to liberate its own territory.

"Putin has to gather his orcs and get out of Ukraine," Bortnik said, using a disparaging term for Russian soldiers frequently used by Ukrainians.

The band was held in Phuket, Thailand in January on immigration charges in a case that has alarmed Russians critical of President Vladimir Putin living abroad.

The organisers of their concerts said all the necessary permits had been obtained, but the band was issued with tourist visas in error and they accused the Russian consulate of waging a campaign to cancel the concerts.

After a week in detention, the band were released and travelled to Israel, where they met with Foreign Minister Israel Katz who said in a statement that the episode showed that "music will win".

Several of their concerts in Russia were cancelled in 2022 after they refused to play at a venue with banners supporting the war in Ukraine, after which they left the country.

"I put my prosperity on the line when the war began and I had to leave Russia. It was unexpected, it was not a process we had prepared for," Bortnik said.

Bortnik said he was more used to emigration than some of his peers who have left in the wake of the war since he moved to Israel while still a teenager.

"I understand how difficult it is," he said.

Bortnik said he was no "geopolitician" and does not write explicitly "political songs" although their lyrics can "hit a nerve that is constantly vibrating".

He said Putin's demise could be sudden and violent and would also bring down Belarusian strongman Alexander Lukashenko, who has been in power for three decades.

"If something happens to Putin then there could be a civil war -- the finale for any tyranny," he said.