Crews searching for the Titan submersible heard banging sounds every 30 minutes Tuesday, according to an internal government memo update on the search.
Four hours later, after additional sonar devices were deployed, banging was still heard, the memo said. It was unclear when the banging was heard Tuesday or for how long, based on the memo.
A subsequent update sent Tuesday night suggested more sounds were heard, though it was not described as “banging.”
“Additional acoustic feedback was heard and will assist in vectoring surface assets and also indicating continued hope of survivors,” according to that update.
A Canadian P3 aircraft also located a white rectangular object in the water, according to that update, but another ship set to investigate was diverted to help research the acoustic feedback instead, according to that update.
The Joint Rescue Coordination Center is working to find an underwater remote operated vehicle to help assist in the search, according to the memo.
CNN has reached out to OceanGate, the US Coast Guard in Boston and Canadian authorities for comment.
Rolling Stone was first to report the news Tuesday night.
CNN’s Andy Rose and Paul Murphy contributed to this report.