North Korean submarine goes missing: Reports

US officials claim North Korea has lost contact with one of its submarines, amid ongoing military exercises by South Korea and the United States in the region.

According to Press TV, reports on Saturday said the vessel, of an unknown class, was last seen operating off the North Korean coast earlier this week.

They cited US military officials as saying that American spy satellites, aircraft, and ships have been watching the North Korean navy search for the missing submarine.

The report said the US military is unsure whether the vessel is adrift or has sunk, but believes it underwent an unspecified failure during an exercise.

The US Naval Institute (USNI) News, meanwhile, has said the vessel was presumed sunk.

North Korea has not confirmed the incident, and has made no comment on the report.

A South Korean Defense Ministry official, whose name was not mentioned in reports, said his country is investigating the reports.