Four people died trying to cross the Channel overnight after the busiest day for small-boat crossings so far this year saw 752 arrivals in the UK.
One man died after a vessel capsized off France’s northern coast late on Wednesday, local officials said, with a one-year-old child among those hurt.
Eight hours later three people were found dead aboard a small boat early on Thursday after launching from Dunkirk overnight, some 100km (62 miles) up the coast.
French officials confirmed their deaths as the Home Office reported that Wednesday had the highest number of crossings in a single day this year, with nine boats reaching the UK.
Local authorities in France said the first boat capsized off the coast at Hardelot around 23:30 local time (21:30 GMT) on Wednesday.
The man is thought to have been in his thirties or forties, officials added. Six other people including the child sustained minor injuries.
Local officials said the vessel was a “taxi” boat – vessels which cruise along the coast and pick up their paying customers who are waiting in the sea.
Security officials “neutralised” the boat and an investigation into the incident has been launched.
The second boat launched from the Dunkirk area overnight and was spotted near a breakwater off the coast at 06:00, the French coastguard said.
Search and rescue officials subsequently found three unconscious people on board. Their deaths were later confirmed by emergency medical personnel.
A UK government spokesperson said: “Every death in the Channel is a tragedy and a stark reminder of the dangers posed by criminal gangs exploiting vulnerable people for profit.”