An international exploration club with members on board the submersible missing near the Titanic wreck suggested “likely signs of life” have been detected, raising hopes that the five-person crew could be rescued.

Richard Garriott de Cayeux, president of the New York-based Explorers Club, said on Twitter that “data from the field” had given the club fresh hope.

“We understand that likely signs of life have been detected at the site,” he said in a statement on the social-media site. “We await hopefully good news.”

De Cayeux didn’t specify what data he was referring to, or provide details about what the “signs of life” were.

De Cayeux’s statement adds fresh urgency to the task of finding the Titan submersible, which has less than 30 hours of oxygen remaining. The Explorers Club said members Hamish Harding, who is the founder of investment firm Action Group and an avid adventurer, and Frenchman Paul Henry Nargeolet are on board the vessel.

While the genesis of the Explorers Club statement isn’t clear, Rolling Stone magazine reported that a Canadian plane with sonar capabilities searching near the missing Titan’s last-known location detected banging sounds at 30-minute intervals. The sounds were heard again four hours later, according to the report, which cited internal updates sent to Department of Homeland Security.

The US Coast Guard didn’t reply to an email seeking comment on any signs of life or the sounds reportedly picked up by a search aircraft.

The Explorers Club said it is continuing efforts to win approval for a specialist remotely-operated underwater vehicle owned by deep-water exploration company Magellan to join the Titan search. Magellan’s equipment can reach depths of up to 6,000 meters (19,680 feet), de Cayeux said in his statement.

“We believe they can provide invaluable assistance,” he said.

Magellan said in a statement on its website that it is “fully mobilized to help.” OceanGate, the company operating the Titanic survey operation and owner of the Titan, asked Magellan to fly necessary equipment and crew to Newfoundland, Magellan said.