VLADIVOSTOK (Russia), Nov 9: Twenty people were killed on board a Russian nuclear submarine, the navy said on Sunday, in an accident that exposed the gap between the Kremlin’s ambitions and its military capability.

The accident, which happened while the submarine was on sea trials in the Pacific Ocean, was the deadliest to hit Russia’s navy since the Kursk nuclear submarine exploded beneath the Barents Sea in 2000, killing all 118 sailors on board.

Prosecutors investigating the latest incident said they suspected the victims died after inhaling a toxic gas used as a fire suppressant when the vessel’s fire extinguishing systems went off unexpectedly.

It was not clear why the portable breathing gear usually issued to Russian submarine crews did not save them.

“Twenty people died,” the Prosecutor-General’s Office said in a statement. “Results of a preliminary investigation show that death occurred as a result of freon gas entering the lungs.”

—Reuters