Article Posted on : - Jan 11, 2015

WASHINGTON (AP): Recent satellite imagery appears to show that a North Korean submarine is being equipped to fire missiles, posing a potential new threat to its neighbours, a US research institute has said.

The finding published by 38 North, the website of the US-Korea Institute at the Johns Hopkins School of Advanced International Studies, comes as Washington ratchets up sanctions against North Korea following a destructive hacking attack against Sony Pictures.

North Korea already has a considerable arsenal of land-based ballistic missiles. South Korea's Defence Ministry reported this week that the North may now have the ability to strike the US mainland because of its progress in missile technology although how far it has progressed remains subject of debate.

The ministry also said the North is advancing in efforts to miniaturise nuclear warheads to mount on such missiles.

Missiles fired from submarines could be harder to detect before launch than land-based ones, and North Korea's efforts have already gotten attention of defence officials. South Korea's military last fall said it had detected a North Korean submarine with a possible capability to launch ballistic missiles.

The institute has previously reported that North Korea was building a missile-testing facility on land near a naval shipyard at the east coast site of Sinpo. Monday's analysis by Joe Bermudez, an expert on satellite imagery and North Korea's military, notes there's been an upgrading of facilities there in the past six months in what appears to be preparation for a significant naval construction programme.

A December 18 commercial satellite image shows a submarine at dock at Sinpo with a large rectangular opening in its conning tower the raised turret that juts vertically from the main body of the submarine.

Bermudez says it could contain one or two missile launch tubes, but the image is not clear enough to deduce what type of missile.

Such a capability could expand the North Korean threat to South Korea, Japan and US bases in East Asia, but developing it will be expensive and time-consuming, Bermudez says.

Experts also say North Korea's submarines tend to be old and would be vulnerable to attack.