Investigators are examining four aluminum fragments and a piece of plastic found on the seabed near the site where the Navy corvette Cheonan sank in an unexplained explosion on March 26. The fragments do not appear to come from the ship itself.
In a session of the National Assembly's Defense Committee on Friday, Defense Minister Kim Tae-young said, "We've collected four metal fragments, aluminum more precisely, from the scene of sinking. They seem a little different from… our hull materials."
"They range from tiny 3 mm pieces to 4-5 cm fragments," he added. "We're examining them to find out whether they are related to an explosive device" that hit the Cheonan.
The body and propeller of a torpedo is usually made of an aluminum alloy or a fiberglass reinforced plastic sheet.
"The collected fragments are different from the outer hull materials of the Cheonan. But we have to examine them further to determine whether they are completely different or from the ship's inner hull," a senior Defense Ministry official said.
The investigation team reportedly found them near the ripped-off parts of the ship's bow and stern. The team believes that a heavy torpedo exploded underwater below the bottom left of the gas turbine room of the ship.
The Cheonan's hull bottom is made of steel sheets, but its upper deck is of aluminum. Precision analysis could reveal if the collected aluminum fragments are part of a torpedo or where they come from.