Iraqi Prime Minister Nouri al-Maliki vowed to fight "until the end" as clashes between government forces and Shiite militiamen continued Thursday, a day after he warned gunmen to surrender their weapons or face harsher measures.
Al-Maliki said the crackdown in the southern city of Basra would continue despite protests and mounting casualties.
"We have made up our minds to enter this battle, and we will continue until the end," he said in a speech broadcast on Iraqi state television.
Although al-Maliki insisted that the Basra offensive is against all criminal groups, supporters of radical Shiite cleric Muqtada al-Sadr believe it is directed at them.
In Baghdad's Sadr City slum, the stronghold of al-Sadr and his Madhi Army, tens of thousands of young men marched through the streets demanding al-Maliki's resignation.
"We will fight whoever attacks the Mahdi Army," chanted the men, many carrying weapons.
Suspected Shiite extremists hit the U.S.-protected Green Zone for the fourth day this week. Rockets and mortars rained down around the area, killing one civilian and wounding 14, according to U.S. military officials.
Fire trucks and ambulances raced through Baghdad to put out fires and collect the wounded. The confusion made it impossible to say for certain how many have been killed or injured in the recent violence. Nationwide, the numbers are in the hundreds.
Mortar attacks on two U.S. bases in Baghdad on Thursday wounded four soldiers, and one American soldier was killed and three injured when their patrols were targeted by roadside bombs.
Violence spread throughout Baghdad neighborhoods as more militiamen claiming to support al-Sadr took to the streets. In New Baghdad, near Sadr City, witnesses said Mahdi fighters were in complete control and that police had fled their posts. In west Baghdad, many police checkpoints were overrun.
Militiamen also kidnapped the Iraqi government spokesman for the U.S.-led surge and then torched his house.
Iraqi Gen. Abdel Aziz Mohammed Jassim, head of military operations, told reporters that Iraqi security forces still have the upper hand, accusing journalists of reporting rumors to the contrary.
Jassim also denied reports that a major oil pipeline had been attacked in Basra, but the strike was later confirmed by Iraq's Southern Oil Company.
Basra resident Ahlam Abdulkader said the city was covered by thick smoke from the pipeline fire. She said people are huddled in their houses as the street fighting between militia fighters and security forces rages outside, and that they are in desperate need of food, medical care and clean water
Abdulkader said she wants the government to establish order in Basra. But al-Sadr's militias are not the only problem, she said, noting that militias associated with the government also have been responsible for killings and corruption.
Sadrists view the government offensive as an attempt by al-Sadr's Shiite rivals to weaken his group before provincial elections planned for this year.
Journalists received messages purportedly from al-Sadr's office stating that the cleric had called on his militiamen to lay down their weapons, but his office called the messages disinformation. One of Sadr's commanders told NPR on Thursday night that he had received orders to fight until al-Sadr's demands — an end to government attacks and the release of detainees — are met.
American officials have cited a cease-fire that Sadr declared seven months ago as a key reason for what had been a drop in violence in recent months. On Thursday, the U.S. military made clear that it is unwilling to say the cease-fire is over, with a spokesman saying the military still believes only rogue Shiite elements are responsible.