Two people have been rescued and a further two are still missing after an incident off the coast near Shoreham this morning.
The UK Coastguard said it was undertaking a search for four people after a man was found in the water two miles from Shoreham Harbour at about 5.50am.
Two coastguard search and rescue helicopters, from Lydd and Lee-on-Solent, have been called along with Coastguard Rescue Teams from Shoreham and Littlehampton and RNLI lifeboats from Shoreham and Brighton.
Several local vessels are also helping to search for the missing people.
A spokesman for the coastguard said it is believed they were in a small vessel and may now be in the water.
The man, who was seen by a fishing boat near Shoreham this morning, has since been rescued.
The spokesman added a second person had also been rescued.
Two others are believed to be missing and searches are continuing.
Andy Jenkins, controller with the UK Coastguard said: “We are carrying out an extensive search for them.”