The boat, which capsized near Calais, had been carrying a group of migrants to Britain.
PARIS — At least 31 people drowned off the coast of France on Wednesday, after a boat carrying migrants trying to reach Britain capsized in the English Channel, according to the French authorities.
Gérald Darmanin, France’s interior minister, said that the dead, including 5 women and a little girl, were part of a group of 33 migrants. There was no immediate word on where the migrants were from.
The death toll, one of the worst for migrants crossing the Channel in recent years, came only a few days after French and British authorities had reached an agreement to do more to stem the number of people taking to the sea.
“The shipwreck that occurred in the Channel is a tragedy,” Jean Castex, the French prime minister, said on Twitter.
Local maritime authorities said they quickly sent out rescue ships and helicopters after a fishing vessel alerted them that several people were lost off the coast of Calais.
“The operation is still ongoing, several of those who were shipwrecked have been picked up,” the French maritime authority for the area said in a statement.
Annick Girardin, France’s minister for maritime affairs, said a British patrol ship as well as Belgian and British helicopters took part in the search, and that five people were still missing as of late Wednesday afternoon.
Natacha Bouchart, the mayor of Calais, told the BFMTV news channel that it was a “human tragedy that I regret and that I’ve been fearing ever since I was elected.” She said she had alerted the central government in recent months that the number of attempted Channel crossings had been increasing.
Philippe Dutrieux, the head of the regional maritime authority, had warned in an interview with Agence France-Presse last week that the number of small vessels trying to cross the Channel had doubled over the past three months, despite dropping temperatures.
As of Nov. 20, 31,500 migrants had attempted the crossing since the beginning of the year, and 7,800 of them had been saved from shipwrecks, Mr. Dutrieux told the news agency, and seven people had died or disappeared so far this year before Wednesday’s incident.
Mr. Dutrieux added that it was near impossible to completely secure a 130-kilometer coastline and stop all migrant vessels from attempting the crossing, and he criticized the “cynicism” of smugglers who “throw migrants into the water because it’s a profitable business.”
“When the weather is nice, you can see the cliffs of Dover, and you get the impression that you can touch them,” he told the news agency.
Olivier Caremelle, a local official and the former chief of staff to the mayor of Grande-Synthe, a town on France’s northern coast that has long sheltered migrants and refugees, said that migrants have increasingly attempted perilous sea crossings over the past year because hiding in trucks taking the Channel tunnel had become more complicated due to tightened security.
Wednesday’s deaths, he said, were “to be expected” given the significant risks presented by the cold seas of the English Channel, heavy shipping traffic and changing weather.
He added that the death toll, which he said was likely one of the highest of the past few years, showed that France’s policy of cracking down on migrant camps near the coast to prevent crossings had failed.
Prime Minister Boris Johnson of Britain said that he was “shocked and appalled and deeply saddened by the loss of life at sea in the Channel.” But, he added: “I also want to say that this disaster underscores how dangerous it is to cross the Channel in this way.”
The French authorities have regularly cleared migrant camps near Calais, offering migrants the opportunity to move to a shelter and file asylum requests. But many migrants prefer to continue their journeys to Britain. One such camp that was home to around 1,000 people in Grande-Synthe was cleared last week.
Migrants will keep trying to cross the Channel, Mr. Caremelle said, and are determined to “get on boats and try their luck in England.” Only a policy that would try to accompany them and find them opportunities in France “would convince some of them not to take such risks,” he said.