A submersible used to take tourists to the wreck of the Titanic has vanished in the Atlantic Ocean.
The sudden disappearance has sparked a search and rescue operation, the Boston Coastguard told the BBC.
It is not yet known how many people were on board the missing craft.
The Titanic wreck lies 3,800 metres down at the bottom of the Atlantic, 400 nautical miles off the coast of Canada.
It sunk in April 1912 after striking an iceberg on its maiden voyage. Of the 2,200 people onboard, just 706 survived.
The wreck was discovered in 1985.
In recent years, small submersibles have started taking tourists to visit the craft. One company – Oceangate expeditions – charges €250,000 per passenger.
The company has confirmed in a statement that it owns the missing submersible and people are on board.
“We are exploring and mobilising all options to bring the crew back safely,” it said. “Our entire focus is on the crewmembers in the submersible and their families.”
“We are working toward the safe return of the crewmembers.”
This breaking news story will be updated as more details emerge.