Two adults and two children have died after a boat carrying migrants sank off the coast of northern France.
A large search and rescue operation began earlier after the vessel was seen in difficulty near Dunkirk.
Two children - aged five and eight - and a man and a woman, believed to be from Iran, have died. Fifteen others have been taken to hospital.
UK Prime Minister Boris Johnson said his thoughts were with the victims' loved ones.
He said: "We have offered the French authorities every support as they investigate this terrible incident, and will do all we can to crack down on the ruthless criminal gangs who prey on vulnerable people by facilitating these dangerous journeys."
media captionDan O'Mahoney said the incident strengthened their resolve to bring those responsible to justice
The stricken vessel was spotted about 2km off the French coast by a passing sailboat at about 09:30 local time, which alerted French authorities.
Four French vessels, one Belgian helicopter and a French fishing boat took part in the rescue and a search operation for people in the water.
Conditions in the English Channel have been rough throughout the day, with a gale warning issued overnight by the Met Office.
An investigation has been opened by the public prosecutor in Dunkirk to try to identify the cause of the sinking.