S. Korean ship likely sunk by external blast

An external explosion most likely sank a South Korean navy ship that split apart three weeks ago, an investigator said Friday, amid concerns about possible North Korean involvement in the disaster.

The 1,090-tonne Cheonan split into two pieces after exploding March 26 during a routine patrol near the tense maritime border with North Korea. Fifty-eight crew members were rescued, but 46 were missing for weeks.

There has been some suspicion but no confirmation of North Korean involvement in the sinking.

The disputed western sea border has in the past been the scene of three bloody inter-Korean naval battles. South Korean officials have said they will look into all possibilities, including that the ship might have been struck by a North Korean torpedo or a mine left over from the 1950-53 Korean War.

North Korean officials have reportedly denied their country's involvement in the blast.

The salvage operation began Thursday, with officials retrieving 38 bodies so far. Eight other remain unaccounted for, according to South Korea’s Joint Chiefs of Staff.

A team of 38 investigators, including U.S. navy officials, conducted a preliminary investigation of the ship's stern after lifting it out of the water.

"There is a high possibility of an external explosion rather than an internal explosion," chief investigator Yoon Duk-yong told reporters Friday. He said further analysis is needed to determine the exact cause of the blast, after salvaging the ship's other wreckage.

The sinking was one of South Korea's worst naval disasters. In 1974, a ship sank off the southeast coast in stormy weather, killing 159 sailors and coast guard personnel. In 1967, 39 sailors were killed by North Korean artillery.