The United Nations Command (UNC) has launched an investigation into whether North Korea violated the Korean War armistice by sinking one of the South's naval ships, the UN body said yesterday. North Korea denounced the probe as a "bogus mechanism".

On Thursday, the South announced the results of an investigation which concluded a North Korean submarine had in March fired a torpedo that sank the Cheonan corvette, killing 46 sailors.

The UNC said in a statement it had convened a special team to review the findings of the investigation and to "determine the scope of the armistice violation" that occurred with the sinking of the Cheonan.

The team, which includes 11 countries - Australia, Canada, Denmark, France, New Zealand, the Republic of Korea, Turkey, the UK and the US, Sweden and Switzerland - would report their findings to the United Nations, it added.

North Korea has denied the sinking accusation and said it is ready to tear up all agreements with the South, with which it remains technically at war under a truce that ended fighting in the 1950-53 Korean War.

"It is the stand of the North side that there is no justification to plug such bogus mechanism as the 'Military Armistice Commission' into the case as it was faked up by the South side to be an issue between the North and the South from its outset," the North's National Defence Commission was quoted as saying by the communist state's official news agency.

Pyongyang said it wanted to send its own investigators across the border, repeating that it would like to make its own assessment of the South Korean investigation.

South Korea's Defence Ministry officials said the government would reject the request. South Korea said after a rare emergency security meeting on Friday it would respond prudently to the sinking of Cheonan, while Washington has called for an international response.

President Lee Myung-Bak is expected to announce his response early this week.

An international response could incude fresh UN Security Council sanctions, although those might be opposed by China.