* Military officials see evidence of external blast
* South Korean president seeks calm in crisis
* Political pressure to mount (Adds military official’s quote, details, paragraphs 1, 8, 10)
By Jon Herskovitz and Jungyoun Park
SEOUL, April 24 (Reuters) - South Korea on Saturday raised the front half of a warship that exploded and sank a month ago near a contested sea border with North Korea, finding clues that support growing suspicions Pyongyang attacked the vessel.
The 1,200-tonne corvette Cheonan sank in what military officials said was likely a torpedo attack.
Forty-six South Korean sailors were killed in what could be one of the deadliest strikes by Pyongyang on its rival since the end of the 1950-53 Korean War. The North has denied involvement.
South Korea’s president on Friday gave the clearest signal yet Seoul had no plan to launch a revenge attack, calming investors worried that armed conflict would damage the South’s rapidly recovering economy. [ID:nSGE63M08C]
"The probably catastrophic costs of a war on the peninsula will greatly constrain the U.S. and South Korean options for a military response, which thus remains an unlikely trigger for major military conflict," the global strategy group Control Risks wrote in a research note this week.
The front end of the ship was raised by a giant sea crane and drained before being placed on a barge.
One body has been found so far in the just-raised wreckage and six sailors were still missing, Yonhap news agency reported. The bodies of most of the 46 missing were found in the stern section raised earlier this month. Another 58 were rescued alive.
"The way a hatch (near where the ship split in two) had been thrown off its hinge indicates there had been a very strong external impact," Yonhap quoted an unidentified military official as saying, adding weight to the torpedo theory.
A survey team that includes experts from South Korea, the United States and Australia said after the rear of the ship was raised the Cheonan had been destroyed by an external explosion. That stoked suspicions of the torpedo attack in waters where the rival Koreas have had two deadly naval fights in the past decade.
Seoul has said it would issue its final verdict on what caused the ship to sink after it had retrieved the front section but has not given a date for releasing its findings.
The sinking of the ship is fraught with risks for South Korean President Lee Myung-bak, who seeks to calm investors, shake off criticism his government tried to deflect suspicions of links to Pyongyang and faces an angry public seeking vengeance.
Lee also needs to prevent turning the affair into a weapon for his political opposition ahead of June local elections. A serious setback in the polls could damage his authority and ability to push through promised pro-business reforms.
The two Koreas, technically still at war, have more than 1 million troops near their border. The United States has about 28,000 troops in the South to support its military.
(Editing by Paul Tait)