Unknown assailants firebombed a historic 18th century Orthodox church in Kyiv and attacked a priest early on November 15, a church spokesman said.
The attack comes amid rising tensions between Ukraine and Russia over Ukraine's move to create a national independent church and sever centuries-old ties with the Russian Orthodox Church.
The Molotov cocktails did not explode and no damage was done to St. Andrew's church, which sits on a steep slope on one of Kyiv's best-known tourist spots.
The church spokesman, Archbishop Yevstraty, said the attackers, whom police said numbered four, used pepper spray against a priest.
Kyiv authorities handed over the use of St. Andrew's to the Ecumenical Patriarch, the global spiritual leader of Orthodox Christianity who sits in Istanbul, while courting the patriarch's support for Ukrainian church independence.
"We see that Moscow's henchmen are dropping clear hints to intimidate representatives of the Ecumenical Patriarch," Yevstraty said.
The Orthodox church in Ukraine is divided between a branch whose clerics pledge loyalty to Moscow and one overseen by the Kyiv-based Patriarch Filaret that Moscow does not recognize.
Ukraine in October secured approval from the Ecumenical Patriarch to set up an independent church, a move fiercely opposed by Russia.
The U.S. Embassy in Ukraine said it was "very concerned" by reports of an attack on St. Andrew's Church.
"We support the right of all religious groups to practice their beliefs free from persecution, interference, or attack," the embassy said on Twitter.
Ukrainian Orthodox Church Firebombed