Ukraine's SBU security service conducted a fresh search of a monastery in the west of the country on Wednesday in what it said was an operation to counter suspected "subversive activities by Russian special services."

The search, in the Mukachevo diocese of the Ukrainian Orthodox Church in Transcarpathia, was the latest in a series of raids conducted in the past week as Russia's war in Ukraine entered its tenth month.

The historically Russian-backed wing of the Ukrainian Orthodox Church announced a formal severing of ties with Moscow in May, but is still mistrusted by many Ukrainians and frequently accused of secret co-operation with Russia.

In the latest search, the SBU said it had inspected the territory and premises of the monastery in the Mukachevo diocese to identify prohibited items and carried out checks on people persons "regarding their involvement in illegal activities to the detriment of the state sovereignty of Ukraine."

It did not say what was uncovered or whether anyone had been detained.

The focus, it said, was on verifying information about the diocese's possible use as a centre of the "Russian world", preventing church premises being used to hide Russian or store prohibited items, and stopping "terrorist acts".

The SBU said last week it had searched 350 buildings belonging to the Ukrainian Orthodox Church and carried out checks on 850 people. It said it found "dubious" Russian citizens, large sums of cash and pro-Russian literature in a raid on a 1,000-year-old Kyiv monastery which Moscow denounced as "godless".

Russia's Orthodox Church said last week the search was an "act of intimidation". The SBU denied this on Wednesday.

"In its work, the SBU adheres to the principle of impartiality towards the activities of any religious denomination and respects the right of every citizen to freedom of world view and religion, as defined by the Constitution of Ukraine," it said.

Russia sent troops into Ukraine on Feb. 24 in what it calls a "special military operation" to disarm its neighbour and protect Russian-speakers. Kyiv and its allies dismissed that as a baseless pretext for a war of aggression. (Reporting by Max Hunder, Editing by Timothy Heritage)