Followers of radical cleric Moqtada al-Sadr fought pitched battles with foreign troops in Shi'ite Muslim strongholds today and vowed to pursue an uprising that has claimed more than 130 lives in three days.
The bloody clashes with Shi'ites that have raged since Sunday are a new front for US-led forces already fighting an insurgency in Sunni areas and trying to pacify Iraq ahead of a June 30th handover of sovereignty to an Iraqi government.
Since Sunday the US military has suffered 19 combat deaths in Iraq - 11 of them in clashes in Shi'ite areas and six in al-Anbar province where Marines have launched a major mission to root out guerrillas in the Sunni cities of Falluja and Ramadi.
Iraqi Foreign Minister Hoshiyar Zebari, in London for talks with British Prime Minister Tony Blair, said thousands more troops might be needed to maintain order.
US Defence Secretary Donald Rumsfeld said if commanders on the ground requested additional forces, they would be sent. "They will decide what they need and they will get what they want," he said.
US polls show a sharp decline in support for the US occupation but President George W. Bush vowed the campaign by Sadr's supporters would not derail Washington's plans for Iraq.
The cleric said he would fight on regardless. "This insurrection shows that the Iraqi people are not satisfied with the occupation and they will not accept oppression," he said in a statement issued by his office in the Shi'ite holy city of Najaf.
The latest reported US death was a soldier killed in a rocket-propelled grenade attack in a Shi'ite area of Baghdad on Tuesday. A Ukrainian soldier and a Bulgarian civilian truck driver were killed in Shi'ite regions of southern Iraq.
In Nassiriya, gun battles erupted between Italian troops and pro-Sadr militiamen who had taken control of key bridges in the town. A spokeswoman for the occupation authority in the area said 15 Iraqis had been killed, mostly militiamen. The Italian military said 12 soldiers had been wounded.
Fighting between militiamen and security forces in Amara, in the British army area of responsibility, killed 15 Iraqis in the last 48 hours, Britain's Ministry of Defence said.
The Bulgarian military base in Kerbala came under heavy fire and Spanish and Polish troops also clashed with militiamen.
Iraq's Health Ministry said 66 Iraqis had been killed and 317 wounded in clashes in Shi'ite areas of Baghdad since Sunday.
Qays al-Khazali, one of Sadr's aides, compared the uprising to a 1991 Shi'ite rebellion eventually crushed by Saddam Hussein and said it would go on until the cleric's demands were met.
"The uprising will continue and we will not negotiate unless they fulfil our demands, which are a withdrawal from populated areas and the release of prisoners," he told a news conference.
A US official said yesterday an Iraqi judge had issued an arrest warrant for Sadr several months ago over the murder of a Shi'ite cleric last year. Sadr's group has denied involvement. Sadr's supporters said he was in his office in Najaf. They would resist any attempt to detain him.
Sadr also appealed to all Iraqis, whatever their religion, to join together to expel occupying troops.
In Falluja, armoured columns of Marines entered the city centre on Tuesday afternoon, in a mission following the killing of four US private security guards in the town last week. Hospital doctors said at least two civilians had been killed in fighting, including a teenage girl, and seven wounded.
US Democratic Senator Edward Kennedy, a key backer of Democrat John Kerry's bid to unseat Mr Bush in November, said Iraq had become "George Bush's Vietnam".
An opinion poll as Mr Bush campaigns for November re-election showed US voter support for his handling of Iraq had fallen to a new low of 40 per cent - down 19 points since mid-January. It also found 44 per cent of Americans wanted US troops withdrawn from the country.
Since the US-led invasion to topple Saddam last year, 429 US soldiers have been killed in action in Iraq.