Twenty-four migrants were seriously injured and many more hurt during the bloody pitched battle, which raged for more than six hours before the gangs were dispersed by heavily armed riot police.
Witnesses reported that knives, metal bars and wooden truncheons were used by the two rival factions, who also set fire to several huts at a notorious migrant camp dubbed 'The New Jungle'.
The gangs, one made up of Eritreans and the other Sudanese, reportedly clashed after a row over access to the best ferry smuggling routes to England boiled over.
Calais-based newspaper Nord Littoral dubbed the brawl a "night of violence" and reported that the vicious fight lasted from midnight until around 6am this morning.
Two squads of France's fearsome CRS riot police rushed to the scene, close to the town's Jules Ferry Centre, where a vast illegal camp stretches across sand dunes into the port town.