Two men, one in his 30s and another in his 40s, died during an overnight Channel crossing, French authorities said. Two more people were injured in the same incident.
The deaths occurred as 12 anti-migrant protesters were arrested on England's south coast after police described "violent disorder" at Gosport. The protesters opposed the rescue of nearly 150 people aboard a second vessel.
Police did not provide further detail on the nature of the violent disorder or the specific circumstances of the arrests.
The incidents took place amid what The Guardian describes as growing unrest in some quarters, partly fuelled by far-right agitators. This unrest persists despite the number of small boat crossings falling in recent months, according to the outlet.
French authorities did not release additional information about the circumstances of the two deaths or injuries in their statement.