According to the government, four migrants perished when their vessel encountered difficulty crossing the English Channel early in the morning.
Nick Eardley of the BBC was told by a source close to the event that 43 individuals had been rescued, including more than 30 from the water.
In frigid waters between Kent and France, a significant search and rescue operation was begun.
“These are the days we fear,” said Suella Braverman, the home secretary.
Earlier, Prime Minister Rishi Sunak expressed his grief at the “tragic loss of life.”
A day after Mr. Sunak pledged increased steps to “stop the boats,” it seems likely that the boat was carrying migrants attempting the trip from France.
A government spokeswoman reported that authorities were informed at 03:05 GMT about a small boat in distress 30 miles west of Dover, off the coast of Dungeness.
Ms. Braverman stated in a statement to the House of Commons that the search and rescue operation was ongoing and that she had discussed the tragedy with Border Force authorities.
The British coastguard, the French navy, the Royal National Lifeboat Institution, and an air ambulance were all dispatched to assist in the rescue operation.
Involved were also a nearby fishing vessel and coastguard helicopters from Lydd and Lee on Solent.
South East Coast Ambulance Service stated it was contacted after receiving reports of the event and dispatched crews to Dover, Kent, to assist with the subsequent operation.
Overnight on Tuesday, the temperature dropped to 1C, and it was certainly colder at sea. At the time, a yellow weather warning for ice was in effect for Kent.
Several lawmakers have offered their sympathies, including Home Secretary Suella Braverman, who stated that her “heartfelt thoughts are with those affected.”
Labour leader Sir Keir Starmer described the news of additional deaths in the English Channel as “heartbreaking,” while Dover MP Natalie Elphicke was “very sorry” to learn of the tragedy.
The operation follows a catastrophic incident in November 2021, in which at least 27 migrants perished when a dinghy carrying them from France to the United Kingdom capsized.
So far this year, about 45,000 people have made the voyage.
The Archbishop of Canterbury tweeted that disputes concerning asylum seekers “are not about statistics, but precious human lives” and that he was “praying for the victims of today’s dreadful tragedy.”
Tim Naor Hilton, from the charity Refugee Action, stated that the tragedy was expected and unavoidable and that more people will perish attempting to reach safety if the government did not establish more avenues for asylum seekers.
