Updated | Three people confirmed to be on board of submersible

A submersible used to take people to view the wreck of the Titanic has gone missing in the Atlantic Ocean.

The Boston Coastguard said it is carrying out a search and rescue operation off the coast of Newfoundland.

It is not yet clear how many people were aboard when the submersible went missing.

Small submersibles occasionally take paying tourists and experts to view the wreck of the Titanic, some 3,800m beneath the ocean surface.

An OceanGate Expeditions submersible similar to the one that went missing

OceanGate Expeditions, a private company that organises deep sea expeditions, confirmed in a statement that it owned the missing submersible and people were on board.

"We are exploring and mobilising all options to bring the crew back safely," it said on Monday. "Our entire focus is on the crewmembers in the submersible and their families."

The company charges guests $250,000 for a place on its eight-day expedition to see the famous wreck.

Who was on board?

So far, three passengers have been confirmed to be on board the Titan: Hamish Harding, a 58-year-old British businessman and explorer, along with Pakistani businessman Shahzada Dawood and his son, Suleman Dawood.

According to a Facebook post by Mr Harding before the dive, French adventurer Paul-Henry Nargeolet is also said to be on board. Stockton Rush, the CEO of OceanGate, is also reportedly on board.

On Sunday, contact with the submersible was lost around an hour and 45 minutes into its dive in the mid-Atlantic. Now, search crews are racing against the clock, but the vessel has yet to be found. OceanGate, the submersible operator, stated that its whole attention was on the crew's safe return.