Russian President Vladimir Putin stood alone at a midnight service at a Kremlin church as he marked Orthodox Christmas darkened by Moscow's assault on Ukraine.
Mr Putin attended the service at the Cathedral of the Annunciation, originally designed as a church for the Russian tsars.
He stood alone as Orthodox priests in golden robes conducted a ceremony holding long candles, pictures released by the Kremlin showed.
In previous years Mr Putin usually attended Orthodox Christmas services in Russian provinces or just outside Moscow.
The Russian Orthodox Church observes Christmas on 7 January.
In a message released by the Kremlin today, Mr Putin congratulated Orthodox Christians, saying the holiday inspired "good deeds and aspirations".
He also praised the Orthodox Church, whose influential head Patriarch Kirill has fully backed Mr Putin's offensive in Ukraine.
Church organisations are "supporting our soldiers taking part in a special military operation," Mr Putin said, using the official Kremlin term for the offensive in Ukraine.
"Such great, multifaceted, truly ascetic work deserves the most sincere respect," he added.
Patriarch Kirill has called on believers to support pro-Russian "brothers" during Moscow's offensive in eastern Ukraine.
In a sermon last year, he said that dying in Ukraine "washes away all sins".
On 24 February last year, Mr Putin sent troops to Ukraine, saying the fellow Orthodox Christian country needed to be "demilitarised."
In recent months, his army has suffered a series of military setbacks on the ground in the Western-backed country.
Mr Putin has unilaterally ordered his forces to pause attacks for 36 hours for the Orthodox Christmas.
But AFP journalists heard both outgoing and incoming shelling in the frontline city of Bakhmut in eastern Ukraine after the time when the Russian ceasefire was supposed to have begun.
Russia-installed official says drone shot down over Crimea's Sevastopol
Meanwhile, the Russian-installed governor of the Crimean city of Sevastopol said today that air defences had shot down a drone in what he suggested was the latest attempted Ukrainian attack on a port where Russia's Black Sea Fleet is based.
Mikhail Razvozhaev, the Russian-backed governor of the city, made the accusation on the Telegram messaging service, alleging that the incident had occurred in the early hours of 7 January, Orthodox Christmas.
"Even the sacred holiday of Christmas was not a reason for these inhuman people to halt their attempts to attack our Hero City," Mr Razvozhaev wrote.
There was no immediate comment on the allegation from Ukraine, which has not in the past confirmed similar alleged incidents but has made clear it reserves the right to do what is necessary to return its own territory.
Russia annexed Crimea from Ukraine in 2014 and Kyiv says it is determined to return the Black Sea peninsula along with a swath of eastern Ukraine and other territory that Russian forces have seized since they invaded last year.
Crimea, which Russia says is now its sovereign territory, was one of the launchpads for what Moscow called its "special military operation" and has come under attack several times - most spectacularly in August, when a series of explosions destroyed a group of warplanes at a Russian naval base.
Mr Putin had proposed a truce to coincide with Orthodox Christmas. Kyiv rejected his offer as a cynical ruse to buy time for Russia's forces to rest and bring in new equipment.
