Japanese Prime Minister Junichiro Koizumi has rejected the demand of Islamic insurgents who are threatening to behead a Japanese captive within 48 hours unless Tokyo pulls its troops out of Iraq.

Kyodo News agency quoted Koizumi as telling Chief Cabinet Secretary Hiroyuki Hosoda that the Self-Defense Forces will not withdraw from the troubled Gulf state. The Prime Minister has also reportedly ordered the Secretary to confirm the facts of the hostage-taking incident and to urgently prepare measures to secure the hostage's release.

A video allegedly posted Tuesday on a militant Islamic website by associates of Jordanian militant Abu Musab al-Zarqawi showed what was purported to be a Japanese captive. The new kidnapping claim, if verified as authentic, would be the third hostage crisis involving Japanese citizens in Iraq.

Insurgents in Iraq have kidnapped more than 150 foreigners. Most were kidnapped for ransom and freed unharmed, but at least 30 have been killed as part of the insurgents' campaign to drive out foreign troops.