An armed group in Iraq has taken a Japanese traveler hostage and threatened to kill him unless Tokyo withdraws its Self-Defense Forces troops from the country within 48 hours, government officials said in Tokyo on Wednesday.

Prime Minister Junichiro Koizumi immediately rejected the demand by the militants, who are linked to al-Qaeda.

"We can't tolerate terrorism. We can't yield to terrorism," Koizumi told reporters in Toyooka, Hyogo Prefecture, where he was visiting the site of severe floods caused by last week's Typhoon Tokage.