The Abu Hafs al-Masri Brigades, in an Internet statement, said Italian Prime Minister Silvio Berlusconi was one of its main targets, adding its forthcoming attacks would not stop until "Iraq is secure."

"Today we have declared the start of a bloody war and, by the will of God, the ground will shake beneath the feet of each and every Italian," said the statement.

Its authenticity could not be immediately verified.

"We call on all our cells to hit all targets in Italy and to strike repeatedly and with strength until this government withdraws (its troops) from Iraq. We will not stop until Muslims can celebrate your exit from Iraq."

The group has repeatedly threatened Italy and has claimed responsibility for attacks, including the Madrid train bombings in March, but has not been officially linked to any of them.

In the statement, the Abu Hafs al-Masri Brigades warned Berlusconi he would "pay with his head for the crimes his troops committed and are still committing in Iraq.

"We declare Berulsconi as our target and ... we will not stop our raids on his country and neither will it enjoy peace until Iraq is secure," it said.

Italian troops are part of the US-led multinational force in Iraq.

US officials say the group's links to al-Qaeda are unclear. But Italy has taken its threats seriously and has renewed security for religious sites after attacks on Christian churches in Iraq earlier this month.

In earlier statements, the Abu Hafs al-Masri Brigades has threatened to launch attacks in Italy similar to the Sept. 11, 2001, attacks al-Qaeda staged in US cities.

The group has denounced European states for their support for US foreign policy and vowed to launch attacks in Europe after a "truce" issued by al-Qaeda leader Osama bin Laden expired in July.

That truce gave countries three months to pull out of Afghanistan, Iraq and other Muslim states or face attacks like the Madrid train bombings, which killed 191 people.

Last week, an Italian interior ministry source said secret services believed a single individual, most likely a north African, was behind all the threats.