Dover is the arrival point for many migrants who cross the English Channel from France in small boats. The number of people making the hazardous journey across one of the world’s busiest shipping lanes has risen sharply in recent years, with 40,000 reaching the UK so far this year, up from 28,000 in all of 2021 and 8500 in 2020.
Dozens have died, including 27 people in November 2021 when a packed smuggling boat capsized.
Britain and France have wrangled over how to stop the people-smuggling gangs that organise the journeys.
The government has announced a controversial plan to send people who arrive in small boats on a one-way journey to Rwanda. Critics say the plan is immoral and impractical, and it is being challenged in the courts.
Immigration Minister Robert Jenrick said he was being kept updated on the incident by police.
“My sympathies are with those involved and my thanks and admiration are with Kent Police and Border Force officers as they go about their essential work to keep us safe.”