French authorities demolished a makeshift church and mosque on Monday at a camp in Calais populated by thousands of migrants.

The operation was the culmination of a two-week effort to clear a 100-meter security zone around the perimeter of the camp, a regional official said. The migrants and charity groups helping them were informed Jan. 19 of the pending demolition, the official said, adding that no one was hurt in the operation.

The pastor for the church clashed with police holding riot shields as excavation machines crushed the simple structure, leaving an empty muddy field beneath.

Rev. Teferi Shuremo said authorities had told him the church was "safe" from demolition.

"They are trying to destroy peace," he said, clinging to a huge wooden cross and pledging to build another church.

The regional official, who wasn't authorized to be publicly named, said the mosque had already been abandoned and no one protested it being razed. He said migrants were free to build new places of worship.

About 4,000 people from Syria, Sudan and other countries are estimated to be at the camp as they try to reach Britain. The French government has come under fire for failing to provide basic care for the migrants, who have built their own shelters, schools, stores and places of worship.