BUCHAREST, Romania (AP) — Millions of Orthodox Christians around the world have celebrated Easter in overnight services and with "holy fire" from Jerusalem, commemorating the day followers believe that Jesus was resurrected nearly 2,000 years ago.

This year the Orthodox churches celebrate Easter on the same Sunday that Roman Catholics and Protestants mark the holy festival. The Western Christian church follows the Gregorian calendar, while the Eastern Orthodox uses the older Julian calendar and the two Easters are often weeks apart.

In predominantly Orthodox Romania, Patriarch Daniel urged Christians to bring joy to "orphans, the sick, the elderly the poor ... and the lonely."

Late Saturday, Orthodox clerics transported the holy flame from Jerusalem by plane and it was then flown to other churches around the country. According to tradition the flame appears each year at the Holy Sepulchre in Jerusalem and is taken to other Orthodox countries.

In Russia, where Orthodox Christianity is the dominant religion, President Vladimir Putin along with Prime Minister Dmitry Medvedev and his wife Svetlana attended midnight Mass at Moscow's Christ the Savior Cathedral.

The cathedral is a potent symbol of the revival of observant Christianity in Russia after the fall of the officially atheist Soviet Union. It is a reconstruction of the cathedral that was destroyed by explosion under dictator Josef Stalin.

In Serbia, the head of the Serbian Orthodox Church, Patriarch Irinej, held a liturgy in Belgrade's St. Sava Temple which outgoing president Tomislav Nikolic attended.

Irinej said in his Easter message that "with great sadness and pain in our hearts, we must note that today's world is not following the path of resurrection but the road of death and hopelessness." He also lamented the falling birth rate in Serbia as "a reason to cry and weep, but also an alarm."

Irinej evoked Kosovo, Serbia's former province which declared independence in 2008. Hundreds of medieval Orthodox churches and monasteries are located there.

Orthodoxy also is predominant in Greece, Bulgaria, Ukraine and Moldova.

AP writers Jovana Gec in Belgade, Serbia, and Jim Heintz in Moscow contributed to this report.