There are now just hours of oxygen left in the missing Titan submersible, as rescue efforts continue for the five passengers.
A Canadian aircraft searching for the sub in the Atlantic Ocean detected intermittent “banging” noises from the vicinity of its last known location, the US Coast Guard said.
Crew searching for the missing sub heard banging sounds every 30 minutes on Tuesday and again four hours later on Wednesday after additional sonar devices were deployed.
However, the US Coast Guard clarified that they “don’t know the source of the noise”.
Rescue teams are facing a race against the clock as the oxygen supply is expected to run out by 1pm UK time on Thursday, as confirmed to The Independent by the US Coast Guard.
Aboard the Titan is CEO and founder of OceanGate Expeditions Stockton Rush, British billionaire explorer Hamish Harding, renowned French diver Paul-Henri Nargeolet and Pakistani businessman Shahzada Dawood and his 19-year-old son Suleman Dawood.
The watercraft submerged on Sunday morning from its support vessel to travel to the Titanic wreckage which sits at a depth of 12,500ft. About an hour and 45 minutes later, the Titan lost contact with its surface ship, the Polar Prince.