Looking weak and speaking with great effort, Pope John Paul II (search) blessed the flame of a tall candle at the start of a long Easter vigil service Saturday night in a packed St. Peter's Basilica. The pontiff baptized people from Europe, Africa and Asia in a solemn, chant-filled ceremony.

The pope's right hand trembled as he poured water from a gold-colored, shell-shaped scooper over the heads of a young man from Italy, a toddler from Togo, two Japanese women in kimonos and three others during baptism.

Earlier, John Paul slowly leaned forward in his chair to insert five grains of incense into the cream-colored candle's wax.

"Very dear brothers and sons, in this most holy night, in which Jesus Christ our Lord, passed from death to life, the Church, spread throughout the Earth, calls her children to hold a vigil of prayer," John Paul said. He then blessed the flame and intoned a prayer in Latin.

John Paul gripped the candle as he was wheeled in his chair up the center aisle of a darkened basilica. Thousands of faithful held small candles whose flames sparked in the darkness. After a deacon's sung phrase, "Lumen Christi" (Light of Christ, in Latin), rang out through the cavernous basilica for a third time, the lights went on in the basilica for the vigil service.

When the vigil service ended, after a little more than three hours, the basilica resounded with applause from the crowd, relieved the pontiff made it through the entire ceremony. The pope mustered the strength to kiss the head of a baby brought to him as he was being wheeled out of the basilica.

The ailing, 83-year-old pope pronounced his words with great effort. But he appeared to gain strength a couple of hours into the service, delivering his entire homily.

He told the new Catholics that they were entering a Church "which is an immense people on a pilgrimage, without limits of race, language or culture."

John Paul suffers from Parkinson's disease (search), which makes speaking and walking difficult. Hip and knee problems also make it impossible for the pontiff to navigate the basilica's sprawling dimensions without assistance.

The vigil service's starting time has been moved up, earlier and earlier, in the last few years, to give the pope more time to rest before Easter Sunday Mass (search). The heavy schedule of Holy Week ceremonies has been a grueling test of the pope's stamina.

Less than 24 hours earlier, the pontiff led prayers at the Good Friday procession at the Colosseum and held a cross passed to him by a young woman from Madrid in a sign of solidarity with those pained by that city's losses in the March 11 bombings.

John Paul is scheduled to celebrate Easter Sunday Mass in late morning on the steps of the basilica before a crowd expected to number in the tens of thousands. The pontiff has often used his Easter message to reflect on such problems as war, terrorism and poverty.

Security has been tight at the ceremonies, with police waving metal-detecting wands over participants and inspecting jackets and handbags. Dogs trained to smell explosives were used to inspect the Good Friday site, and plainclothes security personnel flanked faithful in the basilica in the Saturday night service.

Security at the Vatican, as well as other popular tourist sites in Italy, was heightened after the Sept. 11 attacks.

This year, Orthodox and Catholics were marking Easter at the same time, and in Moscow, the patriarch of the Russian Orthodox Church was quoted as calling this a good opportunity to promote Christian unity.

"All of us must seek Christian unity," Patriarch Alexy II was quoted as saying by the Interfax news agency. Tensions have increased between the Russian Orthodox and Roman Catholic churches since the Soviet Union collapsed in 1991 and communist restrictions on religion faded. The tensions have so far prevented the pope from realizing his goal of a pilgrimage to Russia.