The South Korean navy has begun to raise the stern section of one of its warships¹ which sank after an unexplained explosion last month.

韩国海军将上个月意外爆炸沉没的军舰船尾打捞出海面。

The Cheonan sank in mysterious circumstances

Fifty-eight sailors were rescued at the time of the sinking, which occurred near the sea border with North Korea.

It is thought the bodies of more than 40 missing crew are trapped in the shattered（破碎的，极度疲劳的） hull²（船体，外壳） of the corvette（轻巡洋舰） .

The Cheonan, a 1,200-tonne navy gunboat, sank in mysterious circumstances three weeks ago.

Officials are trying to determine the cause of the explosion; reasons range from accident to attack from the North.

South Korean officials said the stern section would be taken by barge³（驳船，游艇） to a naval⁴ base for a thorough（彻底的，十分的） investigation⁵.

Hazy⁶ view

Early on Thursday, a giant floating crane（水上浮式起动机） winched（用绞盘拉） the stern of the ship up from the sea bed.

Once it has been drained of water it will be examined to try to determine the cause of the blast.

South Korean TV stations are broadcasting images of the salvage⁷ operation（海难救助作业） , with camera crews kept at a safe distance because this section of the ship is thought likely to contain many of the bodies of the missing crew members.

The Cheonan sank close to the sea border which marks North and South Korean territorial⁸ waters.

South Korea has been careful not to level any direct accusations⁹（控告，谴责） against the North, but it is also very clearly not ruling out the possibility that the ship was attacked, reports the BBC's John Sudworth, in Seoul.

President Lee Myung-bak has called for an objective investigation, the findings of which must be beyond dispute, followed by "stern measures" against whoever was to blame.

South Korea's defence minister has renewed speculation¹⁰ a torpedo¹¹（鱼雷，水雷） could have caused the blast.

Kim Tae-young said it was a "likely possibility" the Cheonan had been hit by such a missile, but that all possibilities needed to be considered.

Pyongyang has made no official comment on the incident.

It does not accept the maritime¹² border, known as the Northern Limit Line, which was drawn¹³ unilaterally（单方面地） by the US-led United Nations Command at the end of the Korean War.

The sea border has been the scene of deadly clashes between the navies of the two Koreas in the past.