The Russian Orthodox Church in Ukraine severed its ties to the pro-Kremlin Moscow Patriarchate earlier in the war.
Ukraine is slapping sanctions on 10 senior clerics linked to the Orthodox Church in Moscow on the grounds they agreed to work with Russian occupation authorities or justified the Kremlin's invasion, the security service said on Saturday.
The announcement is the latest in a series of steps against the Ukrainian branch of the Moscow Patriarchate, an Eastern Orthodox church linked historically to Russia. The Moscow Patriarchate itself backs the war.
In a statement, the security services said the 10 clerics had variously agreed to cooperate with occupation authorities, promoted pro-Russian narratives and justified Russian military aggression in Ukraine.
Most of the clerics -- all either members of the church or closely linked to it -- live in territories controlled by Russia or are abroad, the service said.
"The Security Service of Ukraine continues to carry out comprehensive work on the protection of Ukrainian statehood and will continue to expose persons who threaten the sovereignty and territorial integrity of Ukraine," it said.
The Ukrainian branch formally severed ties with the Russian Orthodox Church last May but is still mistrusted by many Ukrainians and accused of secret cooperation with the Kremlin.
The sanctions, which last for five years, will freeze the assets of those on the list, block them from exporting capital from Ukraine and prevent them from owning land.
The security service has also carried out several raids on parishes and buildings linked to the church, which says it has always followed Ukrainian laws.
Orthodox Christians make up the majority of Ukraine's 44 million people.
Since the collapse of Soviet rule, competition has been fierce between the Moscow-linked church and an independent Ukrainian church proclaimed soon after independence in 1991.