BAGHDAD -- As U.S. forces plunged deeper into the bloody showdown between Iraqi security forces and Shiite militiamen, Prime Minister Nouri al-Maliki extended a deadline yesterday for fighters to disarm after nobody responded to his first one.
The United States military said a Navy jet had strafed a mortar-launching position in the southern city of Basra with 20-mm cannon fire Thursday night, killing three "criminal militia members."
It was the first time U.S. forces had been directly involved in the combat in Basra since al-Maliki launched an offensive against militias there on Tuesday.
The U.S. involvement, along with al-Maliki's 10-day extension of the disarmament deadline, were signs that the operation was meeting fiercer resistance than expected even as his government insisted that things were going well.
Loyalists of radical Shiite cleric Muqtada al-Sadr, who say he is being unjustly targeted in the offensive, said the situation had exposed al-Maliki's weakness as a leader.
"That's an indication of his defeat, to call outside forces to strike his own people," said Falah Shanshai, one of 30 national lawmakers from al-Sadr's bloc in parliament. "Force won't do any good. The people are suffering from lack of services, and Maliki brings in the planes."
Baghdad was under a virtual lockdown, its normally chaotic streets quiet except for occasional blasts from rockets and mortar shells thundering into the ground.
"We are scared, sitting home and not knowing what will happen in any minute," said Mithaq Majeed, a Baghdad resident in an area under the sway of al-Sadr's Mahdi Army militia. Overnight, he said militiamen had used bulldozers to build sand hills to seal off the neighborhood.
The developments do not bode well for al-Maliki or U.S. military leaders, who had hoped that the offensive would show that Iraqi security forces can handle major operations without outside help. They also come at a delicate time for the United States, which plans to complete the pullout of 28,500 troops from Iraq by the end of July.
The British military had been in control of Basra until December, when it handed the job to Iraq. Britain has about 4,500 troops in a base on the outskirts of Basra and plans to reduce that number to 2,500 by June. If the situation spins out of control, the U.S. could face pressure to send some of its own forces south. That would thin their presence elsewhere and could affect U.S. withdrawal plans.
President Bush, during a White House news conference, said of the Iraqi forces: "Of course, we'll provide them help if they need it and ask for it, but they are in the lead." He made no mention of U.S. airstrikes the night before.
In Baghdad, U.S. forces also clashed with suspected militiamen in Sadr City, and skirmishes were reported elsewhere. A U.S. military statement said American soldiers had killed 13 terrorists in operations across the capital yesterday, most of them in mainly Shiite eastern Baghdad.
Baghdad and most southern cities were under curfews, which appeared to reduce the violence. Maj. Tom Holloway, a British military spokesman in Basra, said there had been "isolated skirmishes" there.
Police and hospital officials in Basra have put the death toll there since Tuesday at anywhere from 60 to 80, with hundreds wounded. Nationwide, the number of dead, including many civilians, has topped 150, according to reports from different cities.
Al-Maliki deployed forces to Basra, Iraq's second-largest city, saying he wanted to quell fighting by "criminal gangs" he said were engaging in militia activity. But al-Sadr has said the intent was to sideline his movement to ensure it could not defeat pro-al-Maliki forces in local elections planned for the fall.
The U.S. military, which sorely needs al-Sadr to sustain a cease-fire he called in August, has backed al-Maliki's assertion that al-Sadr's forces are not being targeted.
In Baghdad, several mortar shells or rockets believed fired from Shiite areas landed inside the fortified Green Zone, which houses the U.S. Embassy and Iraqi government offices. One hit the office of Iraqi Vice President Tariq Hashimi. He was not at the office, but at least one of his security guards was killed, police said. Earlier police reports had said three guards died.
U.S. Embassy employees were under orders to wear body armor and helmets when going outside and to remain inside fortified structures.
Abdul Kareem Khalaf, a spokesman for Iraq's Interior Ministry, said that "no one handed over his weapons" after al-Maliki issued his first order Wednesday. But he said the ministry, which oversees police, had received calls from people asking how to turn in their arms without facing repercussions.
Khalaf said a formal disarmament system had been established that allows fighters to register at local mosques, instead of having to go to police stations. In a telephone interview, he said anyone handing over weapons would receive a financial reward, but he refused to say how much.
Tina Susman writes for the Los Angeles Times.