Several people died when a boat carrying migrants sank on the English Channel off Calais.
France's Interior Minister Gérald Darmanin said on Wednesday that there was great concern at the drama of the capsizing of the boat.
He will travel to the place of misfortune.
As the broadcaster BFMTV reported, at least five people died.
Other migrants who tried to illegally enter the UK by boat are unconscious.
The Ministry of the Interior did not initially confirm these details upon request.
"It cannot be stressed enough how criminal the smugglers who organize these crossings are," said Darmanin.
As the Maritime Prefecture announced during the ongoing rescue operation, a fishing boat made the emergency call that several migrants were in distress in the English Channel.
Three rescue ships and two helicopters were then used.
Several casualties have since been rescued, some are in mortal danger.
At first there was no mention of the dead.
From the air and by boat, possible further shipwrecked people are searched for in the sea.