BAGHDAD (AFP) - Sophisticated Iranian-built bombs smuggled into Iraq have killed at least 170 US and allied soldiers since June 2004 and wounded 620 more, senior US defence officials have said.

The allegation, made Sunday at a background briefing in Baghdad's fortified Green Zone, comes as Washington steps up its criticism of Iran and will feed a fierce debate over relations with the Islamic republic.

"Iran is involved in supplying explosively formed projectiles or EFPs and other material to Iraqi extremist groups," a senior official from the US-led multinational coalition told journalists.

Three coalition officials met reporters to point the finger at the Al-Qods Force of the Iranian Revolutionary Guards Corps, part of Tehran's elite forces accused of links with foreign militants.

"The Qods Force arms extremists and insurgents to carry out terrorist attacks and guerrilla warfare," he said. "The Qods Force provides advice, training and weapons to proxy forces in Iraq."

The men spoke on condition of anonymity for their security and cameras and recording devices were barred from the briefing, where an array of mortar shells and booby traps were laid out for inspection.

Reporters were issued with a disc containing photographs of alleged Iranian weapons seized in Iraq -- a Misagh-1 ground-to-air missile, EFPs and mortar shells -- showing manufacturing dates in late 2006.

A senior defence analyst said US-led forces had evidence that Iran had stepped up shipments of EFPs, factory-built explosives designed to cut through armour, to armed Iraqi Shiite groups.

He said four Iranians arrested in January in the northern Iraqi city of Arbil were Al-Qods force officers who had no diplomatic cover and had tried to flush docuмents down a toilet as they were arrested.

He added that the Al-Qods force's top operations officer was detained in December in the compound of leading Shiite politician Abdel-Aziz Hakim with an inventory of weapons to be shipped, including mortars and sniper rifles.

Hakim's party, the Supreme Council for the Islamic Revolution in Iraq, told the Americans that the weapons were meant for their protection, he added.

"We assess that these activities are coming from the senior levels of the Iranian government," he said, noting that the Al-Qods brigade reports to Iran's supreme leader, Ayatollah Ali Khamanei.

The senior official said EFPs were a mounting risk on the Iraqi battlefield, and that Iran's involvement was being revealed as a "force protection measure".

"They're pretty devastating," he said, holding up a lump of molten metal that he said had been fired by an EFP through a US vehicle.

"More than 170 US and coalition troops have been killed by these things, and 620 wounded. There was a significant increase in there use over the past six months," he added.

A total of 3,113 US troops have died in Iraq since the March 2003 invasion, according to an AFP count based on
Pentagon figures, with main ally Britain suffering 132 fatalities over the same period.

American and allied troops first encountered Iranian-made EFPs in mid 2004, and since then US commanders have often accused Tehran of fomenting unrest by supplying weapons, cash and training to Iraqi militants.

The device -- one of which was shown to reporters by a senior coalition explosives expert -- consists of a machined steel tube lined with a metal coating and packed with explosives.

When the charge detonates, the metal coating melts and is forced out at high velocity as a white-hot lump, cutting through the armour plating on the target vehicle and spraying the occupants with deadly shrapnel.

Other weapons shown to the press included 81mm mortars with Iranian markings and a distinctive tailfin which a coalition explosives experts described as typical of Iranian munitions.

Until now US officers have been reluctant to confirm the nature of the EFP threat, for fear of encouraging their use and confirming their efficacity to their designers.

There has been mounting frustration, however, at the stark number of US soldiers being killed by the weapons, while most Shiite factions in Iraq's unity government remain on good terms with Tehran.

"We have briefed on this at the highest level of the Iraqi government," said the defence official, "Our message is 'Please go to your neighbour and tell them to stop doing what you're doing'."

The defence analyst said the group who had used the most Iranian built bombs had been a "rogue element" of the Mahdi Army militia, which had split from radical cleric Moqtada al-Sadr to collaborate with Iran.

EFPs have also been shipped to a network run by a former commander in the Badr Organisation -- a semi-official Iraqi militia tolerated by the goverment -- who has since left the force and is now based in Iran, he alleged.

Now they are supplying Iraq, yes.  Our death toll was way down there until Bush started going for Iran.  They're just trying to get us into this war with Iran.

I don't know who all is supplying the Iraqis, but ever since this war with Iran got serious, our forces have been dying in increasing numbers.  Last I heard it is at the rate of three a day.  A very significant increase with a very significant tie in.  Now they are using that to rile us up against Iran, just as they used the sinking of the Lusitania and Pearl Harbor and 9/11.  It's getting to be time that we quit falling for their tricks.

Hmmm.  The question came up in another thread about the value of all this head knowledge.  This is the only thing which makes discovering these truths worth our time---to avoid being tricked into major mistakes.  In my opinion, only a great fool would turn his back on the enemy.