WARSAW, Poland — The spiritual leader of the world’s Orthodox Christians on Tuesday denounced Russia’s invasion of Ukraine as an “atrocious” act that is causing enormous suffering.

Ecumenical Patriarch Bartholomew I didn’t mention Russia by name in comments made during a visit to Warsaw after meeting with Ukrainian refugees. Poland has accepted the largest number of people fleeing the war in Ukraine.

“It is simply impossible to imagine how much devastation this atrocious invasion has caused for the Ukrainian people and the entire world,” Bartholomew said at a news briefing. He added that solidarity with Ukrainians “is the only thing that can overcome evil and darkness in the world.”

Bartholomew also met with Archbishop Stanisław Gądecki, the head of the Polish Bishops’ Conference, who went even further in his denunciation Russian actions which he said bore “the hallmarks of genocide.” Unlike Bartholomew, Gądecki mentioned Russia by name.

Gądecki said Russia’s invasion has resulted in the deaths of “thousands of innocent people” including “hundreds of children, elderly people, women, and men who had nothing to do with the hostilities.”

“Many of the aggressor’s actions bear the hallmarks of genocide,” Gądecki said.

The Polish church leader earlier this month urged the head of the Russian Orthodox Church, Patriarch Kirill, to use his influence with Russian President Vladimir Putin to demand an end to the war and for Russian soldiers to stand down — going further than Pope Francis in his public statements to date.

Istanbul-based Bartholomew is considered “first among equals” among Orthodox patriarchs. Although the titular head of the Orthodox Church worldwide, other Orthodox leaders — including Kirill — are able to wield more power from their base in countries with larger Orthodox populations.

Ukraine’s population is mostly Orthodox Christian, but is divided between an independent church based in Kyiv and another one loyal to Kirill in Moscow.

Kirill and the Russian Orthodox Church severed contact with Bartholomew after the Istanbul patriarch recognized the Orthodox Church of Ukraine as independent of the Moscow patriarch in 2019.

Even though Putin justified his invasion of Ukraine in part as a defense of the Moscow-oriented Orthodox church, leaders of both Ukrainian Orthodox factions have fiercely condemned the Russian invasion, as has Ukraine’s significant Catholic minority.

Bartholomew said it was hard to find words to describe the suffering of the Ukrainians he met in Poland and referred to scripture instead, quoting prophet Jeremiah: “If my head was a spring of water, and if my eyes were a fountain of tears, I would weep all day and night for the slaying of my people.”