Paris: Dozens were hurt on Tuesday after clashes broke out in the northern French port of Calais between hundreds of African migrants seeking to cross the Channel to England.
Police reinforcements were called to break up fights between groups of mainly Eritrean and Sudanese migrants that left 51 people hurt, one of whom was sent by helicopter to hospital with serious head injuries.
"The fights started after dinner and spread to the port area. They lasted most of the evening and into the night," local police authorities said.
One port worker estimated around 300 migrants were involved in running battles in the early hours of Tuesday.
This was the second consecutive night of scuffles between rival groups seeking passage to England. The previous night, 13 people were hurt in fights between around 150 people.
The number of migrants in Calais has grown "by some 50 percent in a few months", local authorities said.
Veronique Devise, from the Secours Catholique charity, said the situation had deteriorated and there was now "a bit of an explosive atmosphere".
"The migrants are so desperate. Sometimes they want to take a lorry by force and head off to England," she said.
According to official figures, nearly 7,500 illegal immigrants, mostly African, have been arrested since the beginning of the year as they attempt to reach Britain.
In May, French police expelled around 550 people from makeshift camps in Calais after a scabies outbreak, drawing criticism from rights groups.