Titanic sub: More noises heard in search area; Crew have less than 20 hours of breathable oxygen left

Experts have not yet identified the source of the noises, and officials have warned that they may not have originated from the missing vessel

An archive picture of the OceanGate Expeditions submersible vessel named Titan used to visit the wreckage site of the Titanic. Rescue teams are continuing the search for the submersible tourist vessel which went missing during a voyage to the Titanic shipwreck last weekend. Picture: American Photo Archive/Alamy/PA Wire

Rescue teams searching for the missing Titan submersible have been focusing their efforts on a remote area of the North Atlantic where a series of underwater noises have been detected. 

However, experts have not yet identified the source of these noises, and officials have warned the sounds may not have originated from the missing vessel itself.