About two dozen people protesting the demolition of a sprawling migrant camp in northern France climbed onto shanty rooftops on Tuesday and were surrounded by a police cordon.

A man and a woman standing together on a rooftop warned police not to approach. The woman then cut her wrists as officers moved forward. Baton-wielding police beat the man and both were removed from the roof. The woman was conscious, but her condition wasn't immediately known.

The slow tear-down of the encampment in Calais has angered migrants who live there in squalid conditions in hopes of reaching a better life in Britain.

France's government, which has offered to relocate uprooted migrants into heated containers or at centers around France where they can decide whether to apply for asylum, blamed activists from the group No Borders for the ongoing unrest. But many migrants resist French offers of help, afraid of hurting their chances to reach Britain.

The city bordering the Channel has ferry links and the Eurotunnel rail to England, and is temporary home to an estimated 4,000 migrants, down from 6,000 in December. The camp has become a flashpoint between France and Britain, fueling far-right support in both countries.

"This operation will continue in coming days, calmly and methodically, providing a place for everyone as the government has committed," French Interior Minister Bernard Cazeneuve said in a statement Tuesday.