The regional prefecture says police conducted the operation at the camp in northern France in the hopes of arresting human smugglers. It wasn't immediately clear if any of the 27 detained were traffickers.
The prefecture said Tuesday that similar raids were being conducted elsewhere in France. Further information wasn't immediately available.
The operation at the camp near the town of Lens was carried out on the orders of an investigating magistrate.
The camp is known to shelter Vietnamese seeking to get to Britain, but unlike other camps in northern France hasn't been dismantled because the land belongs to nearby Angres.
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