North Korea said today it has successfully conducted an underwater test-fire of a submarine-launched ballistic missile, which would indicate progress in the secretive state’s pursuit of building missile-equipped submarines.

The official KCNA news agency said, the North’s leader Kim Jong Un oversaw the test-launch from a location off-shore as the submarine dove under water and a ballistic missile surfaced from the sea and soared into the air, leaving a fiery trail of blaze. There has been no independent confirmation.

North Korea is under United Nations sanctions banning it from developing or using ballistic missile technology.