Brawling has broken out between rival groups of Greek Orthodox and Armenian clerics at the Church of the Nativity in Bethlehem.
Tourists looked on as about 100 priests fought with brooms while cleaning the church in preparation for Orthodox Christmas, on 7 January.
Palestinian police carrying batons and shields broke up the clashes.
Groups of priests have clashed before in the church, which is 1700 years old.
The BBC reports the building is in a bad state of repair, because the priests cannot agree on who should pay for its upkeep.