Knocking sounds: Possible trace in search for submarine Hunter Biden pleads guilty to federal crimes, according to media

Search teams had recorded a kind of knocking sound every 30 minutes on Tuesday in the region where the submarine was suspected, according to an internal memo from the US government, which broadcaster CNN and the magazine “Rolling Stone” reported Wednesday evening (local time).

Four hours later, after additional sonar equipment was deployed, the knocking could still be heard, it said. However, according to the memo, it was unclear exactly when and for how long the sound was heard. A later update, sent Tuesday night, reported additional noises, but they were no longer described as “throbbing,” CNN wrote.

The acoustic sounds indicated there was still hope for survivors, it said. Initially, there was no comment from the Oceangate operating company or the US Coast Guard.

The 6.70 meter small and 10.4 ton vehicle was on its way to the wreck of the Titanic and has been missing since Sunday morning (local time). Authorities estimate that the oxygen should only last until Thursday afternoon (CEST). There are five people on board: French explorer Paul-Henri Nargeolet, British adventurer Hamish Harding and British-Pakistani business consultant Shahzada Dawood and his 19-year-old son Suleman. Captain was the head of the operating company, Stockton Rush. (sda/dpa)