US marines said on Wednesday they were preparing a final assault on Iraqi Shia militia in the holy city of Najaf, after a radical cleric urged his men to keep fighting even if he was killed.
The warning came as sporadic clashes between US troops and militia loyal to Moqtada al-Sadr echoed from the heart of Najaf, where hundreds have been killed or wounded in the past week around some of Iraq's holiest sites.
"Iraqi and US forces are making final preparations as we get ready to finish this fight that the Moqtada militia started," Colonel Anthony Haslam, commanding officer of the 11th Marine Expeditionary Unit in Najaf, said in a statement.
Haslam gave few details, but his threats and Sadr's defiance have raised the stakes in a battle that is the toughest test yet for the 6-week-old government of Prime Minister Iyad Allawi.
In a sign of the growing anger against Allawi and the military action in Najaf, thousands of demonstrators in the southern city of Nassiriya called for him to step down and set fire to the local office of his political party.
Most of Sadr's men and the young cleric himself are holed up around Najaf's ancient Shia cemetery or the adjoining Hazrat Ali Shrine. Storming such holy symbols could touch off a firestorm among Iraq's majority Shia community.
The fighting between US forces and Sadr's Mehdi Army in Najaf is part of a broader Shia uprising in at least seven southern and central cities.
Despite the tightening noose around his men and growing pressure from Allawi, Sadr has refused to surrender.
"Keep fighting even if you see me a prisoner or a martyr. God willing you will be victorious," Sadr said in a statement.
In fresh violence elsewhere, at least six Iraqis were killed and 10 wounded when a bomb exploded in a market just north of Baghdad, hospital sources said. Officials had no further details on the explosion in Khan Bani Saad village.
Clashes also broke out in Baghdad's Shia slum district.
The Shia unrest has disrupted Iraq's vital oil exports and triggered a spike in world prices.
Iraq's exports were running at a reduced rate on Wednesday as engineers repaired a sabotaged pipeline feeding the country's southern terminals, oil officials and a shipping agent said.
The crisis in Najaf also appears to have created cracks in Allawi's administration after Deputy President Ibrahim Jaafari urged US troops to leave the city to end the fighting.
US forces have been pounding Sadr's militiamen with warplanes and helicopters for days.
MARINES HAVE CORDONED OFF THE HOLY SITE: The US military statement said marines; army soldiers and Iraqi National Guards were conducting joint exercises in preparation for major assaults against the militia in Najaf. Sadr said he still wanted Iraq to remain united and thanked "those who tried to resolve the crisis peacefully".
In the past 24 hours, at least 30 Iraqis have been killed and 219 wounded in five cities including Baghdad, the Health Ministry said on Wednesday. The figure did not include Najaf.
US forces say they have killed 360 Sadr loyalists so far in Najaf, home to 600,000 people some 160 kilometres south of Baghdad.
Sadr's spokesmen say that far fewer have died during the second rebellion by the militia in four months.
Fighting erupted again in a Baghdad slum district called Sadr City where armed fighters have roamed at will. Two US tanks thrust into the suburb, pursued by militiamen who fired at least one rocket-propelled grenade at the vehicles.
In the southern town of Amara, British troops backed by planes launched an offensive overnight against Shia fighters that the Mehdi Army said killed 10 militiamen. A British military spokesman said two British soldiers were wounded.
The latest fighting raises questions about what role Sadr wants to play in post-war Iraq, especially ahead of landmark elections scheduled for January. Allawi's attempts to bring Sadr into the political fold appear to have failed, for now.