There are five people in the submarine.
Contact with the small submarine was lost about an hour and 45 minutes after it dived on Sunday. A rescue operation has been launched, but so far there is no sign of the submarine, the BBC reported.
As of Monday afternoon, the crew were thought to have had about four days' worth of oxygen left.
This was reported today by the Russian state news agency TASS.
It is recalled that in January of this year, Moscow announced that it had produced the first set of "Poseidon" torpedoes, four years after Vladimir Putin announced a new type of strategic nuclear weapon, confirming that it would have its own power supply.
Ultra Electronics provides parts for Britain’s Trident-carrying submarines
The deal costs Israel an estimated €3 billion and would see the submarines reach Israeli shores in 9 years