Government and military officials have reportedly ruled out that an accident or collision with a reef caused the 1,200-ton Navy corvette Cheonan to sink in waters 1.8 km southwest of Baeknyeong Island near the de-facto sea border with North Korea on Friday. They say the explosion that sank the ship was strong enough to rip it in half. But experts are divided over whether the blast could have been caused by a torpedo, floating mine or other external shock or an internal accident such as an explosion of ammunition or fuel stored in the vessel.
"The tragedy may have been caused by a floating mine, judging by the explosion in the rear of the ship as well as the situation inside the vessel before it sank and geographic conditions," a government official said. "But we cannot guess the possible cause until we are able to investigate the vessel."
Part of the Navy corvette Cheonan lies on the sea surface during search operations by maritime police in waters near the Baeknyeong Island on Saturday.