Four migrants have died trying to cross the English Channel in small boats, French authorities have said.
In one incident, they said, three women suffered heart attacks after their boat launched off the coast of Dunkirk, northern France.
Separately, a boat sank late on Wednesday off the coast of the French seaside town of Neufchatel-Hardelot, leading to the death of one man.
The women, reportedly aged around 20, 30 and 50, were brought ashore by the French emergency services but attempts to resuscitate them failed and all three were declared dead.
They were on one of the so-called taxi boats operated by human trafficking gangs that are sailed along the coast to pick up people at designated spots before attempting the crossing.
This week, migrants were seen cramming on to small boats off the coast of northern France to take advantage of good weather in the English Channel.
The favourable conditions are believed to have led to hundreds of asylum seekers making the crossing on Wednesday.
The total number of migrants who have crossed the Channel so far this year has reached 13,350, which is around 45 per cent lower than this time last year.
But while the number of migrants has been falling and represents a victory for the UK government, the average number per boat has been rising.
Last year, The National reported the average daily number of asylum seekers per boat was increasing and since reached as high as 100.
The Home Office publishes statistics on the number of migrants who arrive each day and the number of boat, however, it does not publish the number of migrants on each vessel.
This has been attributed to the French authorities intercepting boats and disrupting the supply chain for the vessels' components. That has forced smugglers to cram more migrants on to “mega dinghies” to maintain their profits.
The larger volumes have been blamed for deaths, as more people cram on to the boats, increasing the risk of suffocation or drowning.
A teenager is to face trial after being charged with piloting a “mega dinghy” carrying 165 migrants across the English Channel.
Chan Mathok Atak, 19, from South Sudan, is accused of endangering lives during a journey by sea on July 23.
The number of migrants on board represents the largest known number on a single vessel crossing the Channel, surpassing the previous record of 128.
