A North Korean submarine torpedoed one of South Korea's warships near the disputed maritime border in March, investigators said on Thursday, prompting heated denials and threats of war from the North.

The South's President Lee Myung-Bak promised "resolute countermeasures" and the United States, Britain, the United Nations, Japan and Australia strongly condemned the attack which claimed 46 lives.

The communist North said the report, by a multinational investigation team, was based on "sheer fabrication".

It threatened "all-out war" in response to any attempt to punish it.

"The evidence points overwhelmingly to the conclusion that the torpedo was fired by a North Korean submarine," the team said, releasing its report on the March 26 sinking at a nationally televised press conference.

"There is no other plausible explanation."

Seoul's closest ally the United States called the attack "one more instance of North Korea's unacceptable behaviour and defiance of international law.

Kim's 'all-out war' threat if punished over sinking

Perhaps America's representative on the 'international Investigation', Admiral Thomas Eccles, expects that the world will have forgotten the Gulf of Tonkin incident when a false claim by the US that it had come under fire from North Vietnamese naval vessels was used by then President Johnson as an excuse to expand america's criminal involvement in Vietnam,

It's also a pity that america wasn't as diligent in its investigation of Israel's criminal & unprovoked attack on the USS Liberty in 1967, using 'unmarked' military aircraft.

But who says that credibility is important - they're friends right?