(Reuters) - At least 24 people died after their dinghy capsized on Wednesday while trying to cross the Channel from France to Britain, a local mayor told France 3 television.
Local authorities had previously said five migrants had drowned, but that the tally was likely to increase because several of those rescued were in a serious condition.
"Twenty-four corpses were recovered and 26 people are alive," Franck Dhersin, mayor of Teteghem and vice president of transport for the northern France region was quoted as saying.
French Interior Minister Gerald Darmanin said he was headed there. "Strong emotion in the face of the tragedy of numerous deaths due to the capsizing of a migrant boat in the English Channel," he wrote in a tweet.
Two helicopters and three police or rescue boats were at the scene, local authorities said.
One fisherman, Nicolas Margolle, told Reuters he had seen two small dinghies earlier on Wednesday, one with people on board and another empty.
He said another fisherman had called rescuers after seeing an empty dinghy and 15 people floating motionless nearby, either unconscious or dead.
He confirmed there were more dinghies on Wednesday because the weather was good. "But it's cold," Margolle added.
Early on Wednesday, Reuters reporters saw a group of over 40 migrants head towards Britain on a dinghy.
The Channel is one of the world's busiest shipping lanes and currents are strong. Overloaded dinghies often barely stay afloat and are at the mercy of waves.
While French police are preventing more crossings than in previous years, they have only partially stemmed the flow of migrants wanting to reach Britain in what has become one of the many sources of tensions between Paris and London.