BAGHDAD — Three separate attacks in Baghdad killed four U.S. soldiers and at least 11 civilians, U.S. and Iraqi officials said today.

Three of the soldiers died after their Humvee was hit with an explosively formed penetrator, a type of bomb that the U.S. alleges Iran has been supplying to Shiite militias. Iran denies the accusation.

AP Television News video of the bombing Tuesday in the predominantly Shiite Mashtal neighborhood of eastern Baghdad showed the twisted wreckage of the Humvee burning wildly as soldiers hosed it down with water. Two soldiers were wounded in the attack.

Another soldier was killed and two wounded during combat operations Tuesday in the west of the capital, the U.S. command said.

A roadside bomb rocked an eastern Baghdad Shiite neighborhood early today, killing at least 11 people and wounding 19 others when it exploded next to buses used by morning commuters, police and hospital officials said.

The bombing just before 8 a.m. in Baladiyat left blood, broken glass and shoes on the ground stained the ground around a small crater, AP Television News videotape showed.

Nine people were killed immediately by the blast, according to police, while a medic in nearby Kindi hospital said two others died there shortly afterward from their wounds.

The blast came on the fringes of Sadr City, the neighborhood dominated by anti-American cleric Muqtada al-Sadr, who ordered a six-month suspension of operations by his Mahdi Army militia last week after clashes in the holy city of Karbala between Mahdi Army forces and a rival Shiite militia. U.S. officials believe mainstream Mahdi forces have generally stuck by the order but breakaway factions of the militia are continuing attacks.

In a pre-dawn raid in Karbala on Wednesday, U.S. forces captured an Iraqi believed to be working as the local contact to the Iranian Revolutionary Guards Corps’s elite Quds Force to supply Shiite militias with Iranian-made weapons, said Maj. Winfield Danielson III.

The suspect also is believed to have helped transport Iraqis to Iran for “terrorist training,” Danielson said in an e-mail. The military said it is believed that he is “closely linked to individuals at the highest levels” of the Quds Force.

U.S. forces were led to the suspect, whose name was not released, by information from prisoners, Danielson said.

Ground troops confiscated computer equipment, communication devices, miscellaneous documents and photographs, the military said.

Meanwhile, embattled Shiite Prime Minister Nouri al-Maliki met behind closed doors in the holy city of Najaf with Iraq’s top Shiite cleric, Grand Ayatollah Ali al-Sistani, to brief him on efforts to fill Cabinet jobs vacated when ministers from the largest Sunni Arab bloc and anti-American cleric Moqtada al-Sadr’s movement pulled out to protest the prime minister’s policies.

Shiite politicians never make major decisions without consulting al-Sistani, whose endorsement in the January 2005 election elevated Shiite political parties to power.

The premier told reporters there were “issues which I always find necessary to hear his views on.”

Al-Maliki said he also discussed the possibility of forming a new government altogether or putting together one made up of nonpartisan technocrats — though emphasized it was currently only an “idea” that was being considered among others.

He did not give a time frame for making a decision. But al-Maliki made it clear his government cannot go on indefinitely with an incomplete team of ministers, as has been the case since six Sadrist ministers quit in April over his failure to announce a timetable for the withdrawal of foreign troops in Iraq. The Sunni Arab ministers withdrew in August.

“We are still trying to persuade the (Sunni Arab) brothers to return to their ministries but it seems that they are not likely to do so,” he told reporters. “This, naturally, means the ministries cannot be left vacant.”

Al-Sistani, who rarely leaves his Najaf home, did not speak to the reporters gathered outside his home on a small alley near the shrine of Imam Ali, Shiite’s most revered saint and a cousin of Prophet Muhammad.

Al-Maliki also said he was considering declaring Iraq’s shrine cities “safe havens” where only the army would be allowed to carry arms. He said the proposal was inspired by the fighting last week in Karbala where the clashes between the two rival Shiite militias left at least 50 people dead.

“It’s an idea that will spare us potential problems,” he said, adding that the proposal would cover cities that house all religious shrines regardless of sect.

Elsewhere, officials in Sulaimaniyah announced that they had indefinitely postponed the start of classes for primary and secondary schools in an effort to prevent the further spread of cholera in the northern province.

Since the disease broke out in mid-August nine people have died and some 70 others have been confirmed with cholera. Another 4,000 are suffering from symptoms like severe diarrhea and vomiting.

Cholera is a gastrointestinal disease that is typically spread by drinking contaminated water and can cause severe diarrhea. In extreme cases, that can lead to fatal dehydration. In this case, U.S. military medical officials have said the area water does not seem to be contaminated and it is not yet certain how it is being spread.

Schools, which were due to open Sept. 15, will be kept closed until the outbreak is under control, said Hussein Sheik Mustafa, the provinces educational director.

“This measure is to protect the pupils,” he said in a report in the al-Mashriq newspaper.