A group of four people who survived the disaster told rescuers that they were on a boat that had set off from Sfax in Tunisia and sank on its way to Italy.
The four survivors, originally from the Ivory Coast and Guinea, reached Lampedusa on Wednesday.
More than 1,800 people have lost their lives so far this year in the crossing from North Africa to Europe.
Franck Dhersin, the mayor of Téteghem, near Dunkirk, said a vast rescue operation was launched at about 6am (5am BST) as dozens of boats tried to make the crossing at the same time.
“Several of the boats were facing serious difficulties,” he said.
“Near Sangatte they unfortunately found dead bodies.”
The maritime prefecture confirmed that there had been at least six deaths and said search and rescue operations were ongoing.
“Those who died,” he said, “were not just statistics, but individual people...
“This terrible loss of life demonstrates yet again the need for a system of safe passage to the UK for refugees. This would enable them to apply for asylum while in France, and then to travel safely to the UK without risking their lives in small boats. It would put the people smugglers out of business overnight. We have already seen such a system work for Ukrainian refugees. There is no reason it should not be more widely available.”
winning votes not getting results sorry I Felt i had to point it outConsidering that the UK's deal with Rwanda has cost £180m so far and resulted in the sending of 0 migrants there, not sure why anyone thinks it might be a good idea tbh
Don't think it has tbh, I think the idea is very popular but unless they live near the beaches of Kent or one of the hotels being used to house asylum seekers then this actually has little to no impact on people's daily lives. You can watch the telly or read the papers and get all wound up about it but the next day you still have to go to work, pay your rent or mortgage and buy groceries. And every time someone does that it offers proof of just how badly the party of economic stability and fiscal responsibility has screwed the economy up. A bit of dogwhistling about Stop The Boats isn't going to placate people's anger when they get to the supermarket till and are reminded just how far their money does not go these days.winning votes not getting results sorry I Felt i had to point it out
The UN's International Organization for Migration said in a statement the boat was carrying 86 migrants when strong waves swamped it off the town of Zuwara on Libya’s western coast.
It said that 61 migrants, including women and children, had drowned, citing survivors of the “dramatic shipwreck”.
Libya has in recent years emerged as the dominant transit point for migrants fleeing war and poverty in Africa and the Middle East.
The North African nation has plunged into chaos following a Nato-backed uprising that toppled and killed longtime dictator Muammar Gaddafi in 2011.
The country is a major launching point for migrants trying to reach the European shores through the deadly central Mediterranean.
Yet as 2024 begins, activists and experts told Al Jazeera that 2023 has seen Europe reach for ever more drastic solutions to curb NGO search and rescue operations and outsource its border management to other nations.
The International Organization for Migration (IOM) estimated at least 2,571 people died this year trying to cross the Mediterranean – one of the deadliest years ever. Since 2014, the United Nations agency has counted at least 28,320 men, women and children who lost their lives trying to reach Europe.
“What is new is the popularity of the idea that you can externalise asylum processing,” said Camille Le Coz, associate director for Europe at the Migration Policy Institute. “That’s something we’re likely going to see more of moving forward despite shaky legal grounds.”
Syriza's immigration policy chief said: "We demand in-depth investigation, we demand answers, we demand accountability, and the reason we do it is this.
"We care about all human life, and we cannot get used to the loss of human life."
Giorgos Psychogios told the BBC his centre-left party had called for accountability over coastguard incidents for years, after many reports from international institutions and organisations.
He accused the government of calling his party "anti-Greek", "Erdogan agents" and "provocateurs" for asking those questions.