Reply #11: Initial speculation was a mine, from either NK or SK. Or internal malfunction.

[Prometheus Bound]

South Korea fears mine from north sank ship
Seoul, wary of blaming Pyongyang, says malfunction could have also sunk Cheonan – leaving 46 sailors missing, feared dead

• Tania Branigan in Beijing
• guardian.co.uk, Tuesday 30 March 2010 09.35 BST

A North Korean mine may have caused the explosion that sank a South Korean naval ship near a disputed sea border on Friday night, the south's defence minister said yesterday.

Seoul has been wary in ascribing blame and has also said that an internal malfunction could have caused the disaster that has left 46 crew members missing, feared dead. Pyongyang's state media have made no mention of the incident.

"North Korea may have intentionally floated underwater mines to inflict damage on us," the minister, Kim Tae-young, said, according to Associated Press.

The Seoul-based news agency Yonhap said he told MPs that a device "could have drifted into our area", pointing out that the north planted 3,000 Soviet-made mines in the sea during the 1950-53 Korean war.

"Though many sea mines were removed, it must have been impossible to retrieve them 100% ... One was found in 1959, and another was removed in 1984," he said.

Kim added: "Neither the government nor the defence ministry has ever said that there was no possibility of North Korea's involvement."

Others had suggested one of the south's own mines could be responsible, but the minister said there were none near the Yellow Sea.

Officials also ruled out the possibility of a torpedo attack, citing evidence from the ship's radar operators. They had earlier said that there was no evidence of North Korean military activity in the area at the time of the explosion.

The 1,200-tonne Cheonan split in two within minutes of a blast in the rear hull. It was patrolling the Yellow Sea near Baengnyeong, where several gun battles have taken place between North and South Korean vessels in recent years. But an attack of this kind would be a major escalation of tensions on the peninsula and would anger the US and China.

The South Korean paper Chosun Ilbo quoted experts who cited a range of possible causes. Yoon Yeon, a former commander of naval operations, said an internal explosion could not have caused the disaster, saying that fuses and explosive material would be stored separately in facilities with double or triple locks.
But Baek Seung-joo of the Korea Institute for Defence Analyses disagreed, saying: "If a single torpedo or a floating mine caused a naval patrol vessel to split in half and sink, we will have to rewrite our military doctrine."

One expert suggested the shock from an external explosion could have triggered a second blast inside the ship.
Fifty-eight sailors were rescued, but military officials fear the others were trapped within the rear segment of the ship, now resting 40 metres under water.

http://www.guardian.co.uk/world/2010/mar/30/south-korea-ship-north-mine