South Korea's Cheonan ship sinking mystery: A North Korea mine?

North Korea may have planted an underwater mine to make South Korea's Cheonan ship sink last Friday, the defense minister said. Or an old mine may have been left from the Korean war.

South Korean defense officials put forth one explanation Monday for why a 1,200-ton warship snapped in half last Friday: an underwater mine.

Whether the mine had been left over from the Korean war, or was placed in the ship’s path by North Korea, remains a mystery.

South Korea has not ruled out the possibility that North Korea played a role in the explosion that sank the Cheonan, a South Korean Navy corvette, near the disputed Western sea border between the two countries.

Window for rescue closing

It says it is focusing first on rescue efforts. On Monday authorities continued trying to find 46 sailors believed trapped in the ship’s hull. Local television stations showed footage of the sailors’ tearful families, waiting for news.

“Finding out what happened is actually a second concern at this moment,” says Kim Tae-woo, a veteran analyst at the Korea Institute for Defense Analyses (KIDA). After any surviving sailors are rescued, “then I think there will be some controversy and further debate over responsibility.”

Divers who knocked on the rear part of the vessel at the ocean floor received no response. Defense officials say that any survivors would have had about 69 hours of air – a window of time that was passing when the rescue effort wrapped up Monday around 8 p.m. local time.

Competing theories

Mr. Kim says that while it was possible in theory that a North Korean torpedo or a drifting sea mine left over from the 1950-'53 war sank the Cheonan, there has never been a case of either destroying a South Korean vessel.

“But we know [North Korea] has torpedo boats,” he says.

At a parliamentary briefing on Monday, Defense Minister Kim Tae-young said it was unlikely that a torpedo attack had sunk the ship.

He noted that during the Korean war, the North placed about 3,000 sea mines in the waters surrounding the peninsula, Yonhap reported. He added it was unlikely they had all been removed.

He also said that North Korea “may have intentionally floated underwater mines to inflict damage on us.”

Deadly gunfights have erupted three times in recent years between North and South Korean ships near their Yellow Sea border, as have other skirmishes. In 1967, North Korean artillery fire killed 39 South Korean sailors.

Wire material was used for this report.

[Editor's note: The original version of this story misspelled the name of the ship.]