BETHLEHEM, West Bank (CNN) -- Hundreds of Palestinians and tourists were on hand in Bethlehem on Thursday to welcome the annual Christmas Eve procession of Latin Patriarch , the region's top Roman Catholic cleryman.

With a flourish of bagpipes and drums, the procession ushers in Christmas Eve ceremonies in the town of Jesus' birth, reaching their climax with a midnight Mass later in the day.

Sabbah will preside at the Mass, which is celebrated at the 4th-century Church of the Nativity, built over the cave-like grotto that tradition holds is Jesus Christ's birthplace.

Although the Palestinians gained self-rule in Bethlehem three years ago, Israel still controls surrounding villages and roads leading in and out of the city.

The patriarch's motorcade from nearby Jerusalem, trailed by Christian pilgrims, cleared an Israeli military checkpoint, where an Israeli delegation offered holiday greetings.

Sabbah fanned incense over the altar, and led a service that included prayers in Arabic, English and Latin.

He delivered a sharply political mass, alluding to Israel as the "oppressor" and praying for the release of Palestinian prisoners in Israeli jails. Sabbah also prayed for the "people of Iraq," days after a U.S.-British bombardment of that country.

The nationalist tone of previous Christmases in a Bethlehem under Palestinian authority has been played down: Instead of the 2-story-high Arafat portrait of earlier years, smaller depictions of the Palestinian leader were hanging from streamers over Manger Square.

A hunt for Jamil Jadala, a Bethlehem native accused of involvement in the October killings of two Israelis, was still under way when Palestinian Austhority President Yassar Arafat arrived in Bethlehem early Thursday evening.

Arafat is under pressure from Israel to contain political violence, and Jadala's escape from a Nablus jail earlier this week has embarrassed him.

Police on horseback and Palestinian boy scouts then escorted the procession into town.

Festivities in Bethlehem this year were somewhat subdued by a drop-off in tourism and big millennium renovation projects that have turned the Palestinian town into an open-air construction site.

Although most of Bethlehem's residents are Muslims, the city decorates the streets with Christmas lights and puts up Christmas trees. Banners in English and Arabic read "Merry Christmas!"

Religious rites reflect a diversity of cultures and variety of Christian sects. In Bethlehem, there are Christmas Eve services in English, French, Arabic and Aramaic, the ancient language of Jesus.

In Bethlehem's Manger Square, Christmas Eve draws large crowds of Palestinian locals -- Christians and non-Christians alike -- as well as visitors. The scene resembles an open- air party, with pop tunes blasting on loudspeakers and vendors loudly hawking sweets and steaming ears of corn on the cob.

At midnight, the Mass is shown on large television screens for what is always an overflow crowd outside in the square.

On the outskirts of Bethlehem, quieter observances are staged at Shepherd's Field, near the place where the Bible says herders first learned of the birth of Jesus.

The Associated Press contributed to this report.