Russia and other nations of the Commonwealth of Independent States (CIS) are celebrating Orthodox Christmas Tuesday.

Plunging temperatures and piles of fresh snow didn't stop believers from attending late night services in cathedrals across Russia, and in other nations of the CIS, in advance of Russian Orthodox Christmas Tuesday.

In Moscow's golden-domed Cathedral of Christ the Savior, the head of the Russian Orthodox Church, Patriarch Alexy II, urged thousands of believers to open their hearts to their neighbors. Patriarch Alexy also hailed improved relations between Russia's government and the Orthodox Church and called for those ties to be further strengthened.

Russia's Orthodox church celebrates Christmas according to the Julian calendar and not the Gregorian calendar used by most other Christian denominations in the West.

Religion, Russian Orthodoxy in particular, has taken on renewed importance in Russia since the collapse of the Soviet Union in 1991 and the end of decades of state-sponsored atheism.

President Vladimir Putin, a professed believer in Russian Orthodoxy, was among churchgoers late Monday. He attended services in the Ural Mountains region of Chelyabinsk, where he is on a ski holiday.

Russian state television broadcast pictures showing Mr. Putin lighting candles inside one of the thousands of new churches built across Russia in recent years. Though the church is new, it is built in traditional Russian style, complete with seven golden onion-shaped domes.

While Orthodox Christmas is gaining in popularity, for many Russians the highlight of the holiday season is New Year's, which they mark on January 13, exchanging gifts and celebrating with family and friends.