A frantic search continues for a missing submersible near the wreckage of the Titanic after “underwater sounds” were heard by Canadian aircraft, ABC News reported. The deep-sea submersible, which launched Sunday, is carrying five people in an underwater tour of the Titanic wreckage off the coast of Newfoundland, Canada.

According to ABC News, a source familiar with the situation confirmed that there were reports of “banging” in the search area picked up by sonar.

The underwater vessel, operated by OceanGate Expeditions, lost contact an hour and 45 minutes after submersion. They had 96 hours of oxygen in the vessel. As of Tuesday afternoon, the submersible, called Titan, had 40 hours of oxygen, NBC reported. The U.S. Coast Guard announced Tuesday on Twitter that a Canadian aircraft heard “underwater noises in the search area.”

“Canadian P-3 aircraft detected underwater noises in the search area. As a result, ROV operations were relocated in an attempt to explore the origin of the noises. Those ROV searches have yielded negative results but continue. Additionally, the data from the P-3 aircraft has been shared with our U.S. Navy experts for further analysis which will be considered in future search plans. #Titanic.”

Additionally, the data from the P-3 aircraft has been shared with our U.S. Navy experts for further analysis which will be considered in future search plans. 2/2 #Titanic

— USCGNortheast (@USCGNortheast) June 21, 2023

The United States Coast Guard, Canadian Coast Guard and the Canadian Armed Forces are coordinating efforts to find the 21-foot submersible before time and oxygen run out for those aboard.

A friend of Hamish Harding, former NASA astronaut Col. Terry Virts, said Harding did not talk about risks of his adventures. Virts, on Good Morning Britain, shared the last text he received from Harding: “Hey, we’re headed out tomorrow, it looks good, the weather’s been bad so they’ve been waiting for this.”

British billionaire Hamish Harding is one of the passengers on board the missing Titanic submarine.

‘What was exciting for him about going in this submersible?’ @susannareid100 speaks to Hamish’s friend, Colonel Terry Virts who said they didn’t ‘speak about the risks.’ pic.twitter.com/ctYNuIHk6C

— Good Morning Britain (@GMB) June 20, 2023

The price of a seat on the vessel was $250,000, according to NBC News. It was on its third trip since OceanGate Expeditions began Titanic tours in 2021.