Two migrants died while attempting to cross the English Channel from France to Britain overnight from Sunday to Monday, while two women sustained burns and were taken to hospital, French authorities said.
The two deceased migrants, who were in their 30s and 40s, died during the attempted crossing.
Two women also suffered extensive burns and were transported to hospital. Authorities said their injuries were not life-threatening.
La Voix du Nord, a regional newspaper in northern France, reported that the burns may have resulted from a chemical reaction involving petrol and seawater.
French prosecutors have opened an investigation to establish the circumstances surrounding the deaths.
The latest incident comes less than a week after three people, including a 10-year-old child, died during another attempted Channel crossing.
According to reports, at least 24 migrants have now died along the Franco-British maritime border since the beginning of the year.
France has for years served as a departure point for migrants and asylum seekers without the required visas who seek to reach Britain by sea.
Many rely on smugglers, paying thousands of dollars to board unstable and frequently overcrowded inflatable boats for the dangerous journey across one of the world’s busiest maritime routes.