And the Royal National Lifeboat Institute and the coastguard are also involved in what appears to be a rescue operation, with a helicopter involved.

       The BBC tweeted: "The Home Office confirms to BBC Essex that Border Force is urgently responding to an ongoing incident off the coast of Harwich. The Home Office says that further details will be provided after the initial response and once the situation has been resolved."

       A Home Office spokesman told Express.co.uk: "Border Force is urgently responding to an ongoing incident off the coast of Harwich.

       "Further details will be provided after the initial response and once the situation has been resolved."

       A spokesperson for the Maritime and Coastguard Agency added: "HM Coastguard has been coordinating a search and rescue response to an incident off Essex, working with Border Force and other partners.

       "We sent the coastguard helicopter from Lydd and a coastguard fixed-wing aircraft.

       "HM Coastguard will continue to safeguard life around the seas and coastal areas of the UK, working with search and rescue resources in the area.

       "If a vessel needs search and rescue assistance, HM Coastguard will continue to respond and rescue those in danger."

       Border Force is the official UK agency tasked with securing the nation's borders.

       The RNLI is also understood to have launched one of its boats in a rescue operation.

       While no specific information is yet available, the operation comes at a time when more than 17,000 migrants have attempted to cross the English Channel since the start of 2021.

       Officers enforce immigration and customs controls for people and goods entering Britain.

       They are based at 140 sea and air ports across the UK and overseas.

       Border Force's stated priorities are to:

       (More to follow)