The annual cleaning of one of Christianity's holiest churches deteriorated into a brawl between rival clergy Wednesday, as dozens of monks feuding over sacred space at the Church of the Nativity battled each other with brooms until police intervened.

The ancient church, built over the traditional site of Jesus' birth in Bethlehem, is shared by three Christian denominations — Roman Catholics, Armenians and Greek Orthodox. Wednesday's fight erupted between Greek and Armenian clergy, with both sides accusing each other of encroaching on parts of the church to which they lay claim.

The monks were tidying up the church ahead of Orthodox Christmas celebrations in early January, following celebrations by Western Christians on Dec. 25. The fight erupted between monks along the border of their respective areas. Some shouted and hurled brooms.

Palestinian security forces rushed in to break up the melee, and no serious injuries were reported. A Palestinian police spokesman would not immediately comment.

A fragile status quo governs relations among the denominations at the ancient church, and to repair or clean a part of the structure is to own it, according to accepted practice. That means that letting other sects clean part of the church could allow one to gain ground at another's expense. Similar fights have taken place during the same late-December cleaning effort in the past.

Tensions between rival clergy at the church have been a fact of life there for centuries and have often been caught up in international politics.

In the 1800s, friction between the denominations at the church — each backed by foreign powers — became so fraught that Russian Czar Nicholas I deployed troops along the Danube to threaten a Turkish sultan who had been favouring the Catholics over the Orthodox.

Those disagreements threaten the integrity of the church itself, which was originally built 1,500 years ago and parts of which have fallen into disrepair. Although the roof has needed urgent work for decades, and leaking rainwater has ruined much of the priceless artwork inside, a renovation has been delayed all these years by disagreements among the denominations over who would pay.

Only recently, the Palestinian Authority brokered an agreement to move ahead with replacing the roof, and officials hope work will begin in 2012.