At least 12 people have drowned after a small boat carrying around 70 migrants capsized in the English Channel on Tuesday, just off the northern coast of France near Boulogne-sur-Mer, according to French Interior Minister Gerald Darmanin.

Darmanin added a search and rescue mission was underway involving fire brigade and navy helicopters, several military vessels and two fishing boats.

What do we know so far?

Local authorities said that several other people had been rescued but remain in "serious condition," and warned that the death toll could rise.

"Unfortunately, the bottom of the boat ripped open," said Olivier Barbarin, mayor of Le Portel, a suburb of Boulogne-sur- Mer, where a first-aid post was set up to treat victims. Barbarin had earlier put the death toll at 13.

The boat had reportedly been attempting to cross from France to the United Kingdom when it was spotted in difficulty by a French vessel, the Minck, which had gone to its aid before it broke up, the Minck's captain Etienne Baggio told the AFP news agency.

Sea temperatures in the area were around 20 degrees Celsius (68 Fahrenheit).

"It's a huge drama," said Mayor Barbarin of what is the most deadly single incident in the English Channel involving migrants this year.

Some 25 people had already lost their lives attempting the crossing since January, already surpassing the 12 deaths recorded in the whole of 2023.

Barbarin said that the town's out-of-use hoverport had been opened up for use by rescue helicopters.

According to the local Voix du Nord newspaper, Interior Minister Darmanin is expected in Boulogne-sur-Mer this afternoon.

"All government services have been mobilized to find the missing and take care of the victims," Darmanin wrote on social media. "I am on my way to meet elected officials and the emergency services."

Migrant aid group criticizes French government

The migrant aid campaign group Utopia 56 has criticized the French authorities over their management of the migrant crisis on the Channel coast, accusing them of contributing to deadly incidents.

"There have been deaths in the Channel every week for two months now," said spokeswoman Charlotte Kwantes, telling AFP that "repressive policing" in coastal areas was "completely ineffective" and that it "leads to these sorts of tragedies."

Six migrants died in three separate incidents in one week in July: four on July 12, one woman on July 17 and one man on July 19.

Another young woman was crushed to death on an overcroweded boat at the end of July, before two more people were declared dead on near Calais on August 11.

mf/wmr (AFP, AP)