Seoul: South Korea on Thursday accused the North of sinking a Navy ship last March, saying the evidence was overwhelming and that it would take "firm" measures against its isolated neighbour.
The North called the report by international investigators a fabrication and warned that it was prepared to go to war if the South takes sanctions against it, South Korea`s Yonhap news agency reported.
A joint civilian and military investigation team, that included experts from the United States, Australia, Britain and Sweden, concluded that a North Korean submarine fired the torpedo that sank the Cheonan corvette, killing 46 sailors.
"There is no other plausible explanation," it said.
The US White House said it backed the report`s conclusion, calling the "act of aggression" another sign of the North`s unacceptable behaviour.
A senior government official said previously that the attack appeared to have been in revenge for a firefight near their disputed border late last year in which the North`s Navy was humiliated.
President Lee Myung-bak called an emergency meeting of his National Security Council for Friday. His government has already made clear it has no plans for a retaliatory strike of its own but will be pressing the international community to take action against the reclusive North.
"We will be taking firm, responsive measures against the North, and through international cooperation, we have to make the North admit its wrongdoing and come back as a responsible member of the international community," Lee was quoted by his office as telling Australian Prime Minister Kevin Rudd.
Seoul financial markets showed muted reaction to the widely anticipated conclusion.
Parts of the torpedo recovered from the scene, off the Korean peninsula`s west coast, were compatible with a North Korean-made weapon that South Korea secured seven years ago, the investigation report said.
The report, announced in national televised news conference, said intelligence had shown that North Korean submarines were likely in operation near the scene of the sinking, with similar vessels of other neighbouring countries all inside their territorial waters.
"Based on all such relevant facts and classified analysis, we have reached the clear conclusion that (South Korea`s) Cheonan was sunk as a result of an external underwater explosion caused by a torpedo made in North Korea," the report said.
"The evidence points overwhelmingly to the conclusion that the torpedo was fired by a North Korean submarine."
N Korea warns
North Korea warns that it will wage "all-out war" if punished for the sinking of a South Korean warship.
North Korea`s official Korean Central News Agency quoted a spokesman from the National Defence Commission as refuting the findings as a "fabrication”.
The report says Pyongyang will react to any punishment or sanctions with warfare.
The US accused Pyongyang of indulging in aggression and defiance of international law following the investigation report.
"It points overwhelmingly to the conclusion that North Korea was responsible for this attack. This act of aggression is one more instance of North Korea`s unacceptable behaviour and defiance of international law," White House Press Secretary Robert Gibbs said in a statement minutes after the results of the investigations were made public in Seoul.
"This attack constitutes a challenge to international peace and security and is a violation of the Armistice Agreement," he said.
US President Barack Obama has expressed his deep sympathy to South Korean President Lee Kyung-Bak and Korean people for the loss of 46 sailors on the Republic of Korea Navy ship Cheonan that was sunk on March 26 by a torpedo, he said.
(With Agencies’ inputs)