(Bloomberg) -- Lithuania said two Polish citizens had been detained over an attack on an ally of the late Russian opposition leader Alexey Navalny in the Baltic nation’s capital last month. 

Leonid Volkov was assaulted with a hammer near his home in Vilnius in what the authorities consider to be a politically motivated incident. Prosecutors said they expected the suspects, who arrived in Lithuania before the violence and left shortly after for neighboring Poland, to be handed over next month following their detention in Warsaw on April 3. 

“There’s information supporting the belief that the victim was injured because of his political activities and his views,” Justas Laucius, chief Vilnius prosecutor, told reporters on Friday.

In a post on social media platform X, Volkov thanked the Lithuanian authorities for their “tremendous work.” 

Polish Prime Minister Donald Tusk said in a post on X that the two detained men had been recruited by a citizen of Belarus, who was working for Russia.

Authorities in Poland said on Thursday that they had arrested a man on suspicion of assisting with a Russian plot to assassinate Ukrainian President Volodymyr Zelenskiy.

“There will be no leniency for collaborators of the Russian services,” Tusk said. “We will nip in the bud any betrayal and attempt at destabilization.”

--With assistance from Natalia Ojewska and Piotr Bujnicki.

(Updates with details from prosecutors from first paragraph. comments from Polish premier from fifth paragraph)

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