Calais police crackdown on migrants
French police held nearly 200 people without papers in a mass identity check around Calais.
The local government said the sweep was meant to find smugglers and undermine networks of illegal immigrants.
Among those checked, 194 were in France without permission.
Immigration Minister Eric Besson plans to visit Calais, a magnet for migrants trying to get to Britain, on Thursday.
He is to announce proposals on dealing with the growing humanitarian problem there and make good on his promise to "seal" the border against illegal immigrants.
With the 2002 closure of a shelter near Calais, migrants have no refuge and the UK wants migrants to stop using Calais as a springboard.