Several people have been rescued by lifeboat crews following an attempted small boat crossing in the Channel.
Details about whether there were injuries and the number of people involved had yet to be confirmed.
The coastguard helicopter and the RNLI are among those who were alerted.
Photographs of the scene showed groups of people being brought in to Dungeness, Kent, by an RNLI lifeboat.
One person was pictured being taken away from the shore on a stretcher.
A UK Government spokesman said: “We can confirm there is an ongoing response in the Channel inside French waters.
“French authorities are leading, and we will not be commenting further at this stage.”
An RNLI spokesman said “an RNLI lifeboat was tasked this afternoon and the rescue is ongoing”.
A spokesman for the Maritime and Coastguard Agency said: “HM Coastguard is currently working with the French Coastguard who are co-ordinating the response to an incident involving a small boat in the French search and rescue region, working with Border Force and other partners.
“HM Coastguard will continue to work with partners to respond to those in distress around the seas and coastal areas of the UK.”
The incident followed reports that two migrants drowned earlier on Wednesday after a small boat packed with 60 people capsized two hours after leaving the French town of Neufchatel-Hardelot.
Steve Valdez-Symonds, Amnesty International UK’s refugee and migrant rights director, said: “We are heartbroken by this loss of life and our immediate thoughts are with the family and friends who have lost their loved ones.
“The new Home Secretary must finally be the one to face up to reality.
“People will continue to attempt dangerous Channel crossings while they are without safe access to fair and efficient asylum procedures on each side of the water – including safe routes to the UK for people whose family and other connections are here.
“We urge ministers to radically change their focus – rather than trying to avoid all responsibility for asylum, the UK must accept its part in providing safety and encourage other countries to do the same.”
Enver Solomon, chief executive of the Refugee Council, said: “This is yet another appalling and preventable tragedy that demonstrates yet again the urgent need for safe routes so men women and children from countries such as Afghanistan don’t have to take dangerous journeys across the world’s busiest shipping lane.”
