Poland has arrested nine people in connection with acts of sabotage committed in the country on the orders of Russian services, Prime Minister Donald Tusk said late on Monday.

Warsaw says its position as a hub for supplies to Ukraine has made it a key target for Russian intelligence services, and accuses Moscow of trying to destabilise the country.

“We currently have nine suspects arrested and charged with engaging in acts of sabotage in Poland directly on behalf of the Russian services,” Tusk told private broadcaster TVN24.

“This includes beatings, arson and attempted arson.”

He said Poland was collaborating with its allies on the issue and that the plots also affected Lithuania, Latvia and possibly also Sweden.

Tusk said earlier this month Poland would allocate an additional 100 million zlotys ($25.53 million) to its intelligence services due to the threat from Russia.

In April, two people were detained in Poland on suspicion of attacking Leonid Volkov, an exiled top aide to late Russian opposition leader Alexei Navalny.