Baghdad, Iraq ? U.S.-backed Iraqi forces stormed the Health Ministry and arrested its No. 2 official Thursday, accusing him of diverting millions of dollars to the biggest Shiite militia and allowing death squads use of ambulances and government hospitals to carry out kidnappings and killings.

Shiite politicians allied with anti-American cleric Muqtada al-Sadr denounced the arrest of Deputy Health Minister Hakim al-Zamili as a violation of Iraqi sovereignty and demanded that the prime minister intervene to win his release.

But Prime Minister Nouri al-Maliki and his senior advisers remained silent. Al-Maliki, a Shiite, is under strong U.S. pressure to crack down on Shiite militias and has pledged not to interfere in the security operation to rid Baghdad’s streets of gunmen from both Islamic sects.

The arrest took place at 9 a.m., an hour after Iraqi government offices generally open. Iraqi troops pushed through the iron gates of the Health Ministry building in northern Baghdad, ordered people to drop to the ground and rushed to al-Zamili’s ground-floor office, witnesses said.

One of al-Zamili’s bodyguards said American soldiers accompanying the force asked everyone to step aside and approached the deputy minister, who introduced himself. A U.S. soldier handcuffed al-Zamili and led him away, the guard said on condition of anonymity because he feared reprisal.

AP Television News footage of al-Zamili’s office showed overturned chairs and smashed computers along with scattered files and telephones on the floor. Dusty, white boot prints marked the door, apparently because the troops had kicked it in.

A U.S. military statement did not mention al-Zamili by name but said Iraqi special troops captured a “senior official” suspected of alleged corruption and links to al-Sadr’s Mahdi Army militia. The Health Ministry is among six Cabinet posts controlled by al-Sadr, an ally of the prime minister.

American officials had long complained that al-Sadr’s followers were transforming hospitals into bases for the Mahdi militia and were diverting medicine from state clinics to health care facilities run by the cleric’s movement.

The clinics helped al-Sadr build a powerful nationwide political movement modeled in part on the Shiite Hezbollah militia in Lebanon.