A massive search and rescue effort is under way in the North Atlantic after a submersible exploring the wreck of the Titanic went missing on Sunday (Jun18)

The research vessel Polar Prince lost contact with the crew of the Titan sub an hour and 45 minutes into its dive. Search authorities estimate that the sub has fewer than 30 hours of oxygen left - meaning supplies are set to run out by around 10:00 GMT (06:00 EDT) on Thursday.

Updates on the missing OceanGate submarine looking at Titanic wreckage (Video)

A Canadian aircraft has now detected "underwater noises" in the search area.

Tour firm OceanGate says it is exploring all options to get the crew back safely, and government agencies have joined the rescue operation. Here is what we know so far.

The current position of the research vessel Polar Prince you can find on VesselFinder website here

What is the latest on the rescue effort?

In the early hours of Wednesday, the US Coast Guard said Canada's P-3 search plane had detected "underwater noises in the search area".

"As a result, ROV (remotely operated vehicle) operations were relocated in an attempt to explore the origin of the noises. Those ROV searches have yielded negative results but continue," the coast guard tweeted.

Earlier, two US media outlets had reported a leaked US Department of Homeland Security memo which said "banging sounds" had been detected by another Canadian aircraft, a P-8, equipped with underwater detection capabilities.

As of Tuesday afternoon local time, US and Canadian forces and private vessels had searched a 7,600 square mile area, roughly the size of the US state of Connecticut, according to US Coast Guard Capt Jamie Frederick.

Capt Frederick said the search was "very complex" and a "unique operation" made more difficult by the remoteness of the area.

A commercial pipe-laying ship has also arrived in the area to help, said David Mearns, a marine scientist and expedition leader who has been following the operation.

"We're just hoping that it has the capabilities to reach those kind of depths - 3,800 metres - to search for the submersible and have the ability to recover it," he told the BBC. "There is some hope that that could happen."

Sources: BBC / YouTube Fox13 Seattle