North Korea has developed a new type of midget submarine fitted with torpedo launch tubes, allowing it to attack South Korea warships more easily, a report said Tuesday.

Satellite images of a naval base in the North's southwestern city of Nampo, published by JoongAng Ilbo newspaper, show what appears to be a 17-metre-long (56-feet) submarine with a tube-like structure attached to its top.

"We have concluded that it is a torpedo launch tube," the paper quoted an unidentified Seoul intelligence source as saying.

The paper said the new Daedong-B midget submarine moves faster than larger submarines and is harder for military radar to detect.

The South accused the North of sending a 29-metre Yono-class submarine to torpedo the Cheonan warship in March which sank with the loss of 46 lives. The North denies the charge.

The newspaper said the North has long used midget submarines to infiltrate spies into the South. It said Seoul military officials now suspect Pyongyang has developed a more powerful midget sub to carry torpedoes and other weapons.

South Korea's defence ministry and intelligence agency declined to comment.

Cross-border tensions have been high since the Cheonan incident, and rose further after the North's deadly artillery attack on a South Korean border island on November 23.

earlier related report
China slams report that it is 'enabling' N.Korea
Beijing (AFP) Dec 7, 2010 - China on Tuesday slammed a report that the United States has accused Beijing of "enabling" North Korea to start a uranium enrichment programme and to launch attacks on the South as "irresponsible".

The Washington Post reported late Sunday, citing an unnamed senior US official, that China had encouraged the hardline regime in Pyongyang to "behave with impunity".

"We feel the accusation is irresponsible," foreign ministry spokeswoman Jiang Yu told reporters. "China's efforts (to maintain peace and stability) have been witnessed by all."

"I want to stress that on issues relating to peace and stability, we are against any action that undermines stability. We do not seek to protect any side," she said.

North Korea shelled a South Korean border island on November 23, killing two marines and two civilians, and then it revealed a uranium enrichment programme that alarmed US scientists.

China is North Korea's only major ally, and the impoverished country's economic and political lifeline.

The Washington Post report indicated a change of tack by the administration of US President Barack Obama in its approach to China, suggesting the White House was quickly losing patience with Beijing.

"The Chinese embrace of North Korea in the last eight months has served to convince North Korea that China has its back and has encouraged it to behave with impunity," the paper quoted a senior administration official as saying.

"We think the Chinese have been enabling North Korea."

In the wake of the shelling, Beijing called for emergency talks among the envoys to stalled six-nation negotiations on North Korean denuclearisation, which involve the two Koreas, China, Japan, Russia and the United States.

But Washington, Seoul and Tokyo baulked, instead holding their own three-way meeting in the US capital on Monday, at which they called on Beijing to help rein in its wayward ally.

"We appreciate Beijing's initiative to propose an emergency six-party gathering. However, we first need an appropriate basis for the resumption of talks," US Secretary of State Hillary Clinton said.

South Korean Foreign Minister Kim Sung-Hwan added: "We would like China to have a more clear stance in giving warning to North Korea and to contain these provocative actions by North Korea."

When asked for China's response to being excluded from the talks in Washington, the foreign ministry spokeswoman again called on its regional partners to agree to wider negotiations.

"The responsibility for safeguarding peace and stability should be shouldered by all parties in the region. We call on all parties to positively respond to our proposal for talks," Jiang said.