US marines, backed by aircraft, launched a major offensive to crush a week-long rebellion by Shi’ite militia dug in around holy sites in the Iraqi city of Najaf yesterday.

Thousands of civilians were fleeing the area around Imam Ali Shrine in the heart of the city, witnesses said. A message in Arabic read out from Humvees said: “To the residents of Najaf: Coalition forces are purging the city of Mehdi Army.”

US tanks were blocking all roads leading to the shrine, one of Shi’ite Islam’s holiest sites, as US aircraft and artillery pounded a nearby cemetery, a stronghold for the militiamen loyal to radical cleric Moqtada al-Sadr.

The fresh fighting comes after seven days of efforts by US and Iraqi government forces to root out Sadr’s troops. A threat by Sadr’s militia kept a main southern oil export pipeline shut yesterday although crews had repaired it after sabotage stopped operations for three days, an oil official said.

A senior official from Sadr’s Mehdi Army, Sheikh Asaad al-Basri, had warned that militiamen would blow up pipelines in the south if US forces tried to storm their Najaf bases. Oil prices climbed after the threat, with US light sweet futures up six cents to $44.58 in floor trade, more than $1 up from the day’s low.

Warplanes and helicopter gunships pounded the outskirts of Najaf’s cemetery as troops blocked off all roads leading to Imam Ali Shrine yesterday, and gunmen responded by firing rocket-propelled grenades and mortar bombs at US positions, witnesses said.

“The fighting is very heavy. I see smoke rising from the cemetery and warplanes circling overhead,” one resident said. Two tanks and four Humvees advanced some 500 metres into the old part of the city near the Imam Ali Shrine, where hundreds of militiamen are deployed, the resident said.

Most of Sadr’s men and the young Muslim cleric himself are holed up around Najaf’s ancient Shi’ite cemetery or the adjoining Imam Ali Shrine. Storming such holy symbols could touch off a firestorm among Iraq’s majority Shi’ite community.

<B>Angry demonstrators</B>

Some 2 000 US servicemen and 1 800 Iraq security men are deployed around Najaf, a city of 600 000 about 160 km (100 miles) south of Baghdad.

Thousands of Sadr’s supporters vented their anger against interim Prime Minister Iyad Allawi in the streets of Nassiriya and several other cities on Wednesday. In Nassiriya, one of seven cities where a radical Shi’ite uprising has taken hold in the past week, demonstrators torched Allawi’s political party office and called for his downfall.

In fresh violence elsewhere in Iraq, the Iraqi Health Ministry said on yesterday that 25 people were killed and 153 wounded in fighting in Baghdad and its suburbs in the past 24 hours. Sadr’s followers have also clashed with US forces in Shi’ite suburbs of the capital.

Despite the tightening military noose, Sadr has refused to surrender. The latest fighting has shattered a two-month truce between US forces and their most vocal critic in Iraq.

“Keep fighting even if you see me a prisoner or a martyr. God willing you will be victorious,” Sadr said in a statement on Wednesday. US forces say they have killed 360 Sadr loyalists so far in Najaf. Sadr’s spokesmen say far fewer have died in what is the second rebellion by the militia in four months.

Khaled Farhan