The Islamic militant group blamed for deadly attacks on foreign and local interests in Iraq threatened Japan (search) on Tuesday that car bombs would strike its troops if they were not withdrawn.

"To the government of Japan: do what the Philippines (search) has done. By God, nobody will protect you and we are not going to tolerate anybody," said an online statement signed by the Khalid bin al-Waleed Brigade, the military wing of the Tawhid and Jihad group.

"Lines of cars laden with explosives are awaiting you; we will not stop, God willing," said the statement, carried by an Islamic forum, known as a clearinghouse for statements by extremist groups.

"You didn't come to support the people of Iraq but to protect the Americans. Your destiny will be the same of Americans," the statement said.

Japan has dispatched about 500 troops to southern Iraq for non-combat duty to rebuild local schools, provide medical supplies and supply clean water. The military mission, begun earlier this year, is controversial in Japan as its first to a combat zone since World War II (search).

In April, Japan refused to withdraw its troops after three Japanese were kidnapped by Iraqi insurgents. The three were later released.

But the Philippines gave into kidnappers' demands, withdrawing its 51-member contingent after a Filipino truck driver was taken hostage. The man was freed Tuesday. Manila's acquiescence angered Iraqi and American officials, who said it would only encourage the terrorists.

Tawhid and Jihad is considered one of the most dangerous groups fighting coalition forces in Iraq. The group, led by Al Qaeda-linked militant Abu Musab al-Zarqawi (search), has claimed responsibility for attacks on U.S. troops and Iraqi police and security forces that have killed hundreds, as well as the beheading of American, Bulgarian and South Korean hostages.

The group's statement also warned Arab and Islamic governments not to deploy troops to Iraq, naming Jordan, Iran, Turkey and Gulf countries.

"We are warning you for the last time: We will hit with a fist of iron all those supporting the Americans or [interim Iraqi Prime Minister Iyad] Allawi or his cronies," the statement read.

Addressing the soldiers of Islamic and Arab governments, "we call upon you to disobey if you were ordered to be deployed to Iraq."

On Sunday, al-Zarqawi offered a reward of $280,000 to anyone killing Allawi.

U.S. authorities last week have raised to $25 million a reward for information leading to the arrest of al-Zarqawi.