BAGHDAD, Iraq - Less than two weeks ago, the U.S. military praised an Iraqi raid to clear insurgents from an area southeast of the capital as evidence of the country's progress in assuring its own security. On Friday, the insurgents struck back.

In one of a series of highly coordinated attacks across Iraq, militants detonated a roadside bomb in the town of Madain, 12 miles southeast of Baghdad, then sent two suicide car bombers from two different directions into police as they arrived to investigate. At least two more car bombs detonated, one near the city hospital and another targeting a police patrol.

Altogether, insurgents set off at least 17 bombs in Iraq on Friday, killing at least 50 people, including three U.S. soldiers in strikes aimed at shaking Iraq's newly formed government. An audio tape by one of America's most-wanted insurgents, Abu-Musab al-Zarqawi, warned President Bush there was more bloodshed to come.

The attacks, which also wounded 114 Iraqis and seven Americans, came as political leaders were trying to curb the insurgency by including all of Iraq's main religious and ethnic groups into an uncertain new Shiite-dominated government that takes office Tuesday. Most of the bombing targets were Iraqi security forces and police, whom insurgents accuse of collaborating with the Americans.

An association of Sunni Muslim clerics believed to have links with the insurgency saw little prospect for peace as long as U.S. forces remain in Iraq.

"We don't believe that the government will solve the problems of an occupied Iraq. We don't trust the government," Harith al-Dhari, head of the Association of Muslim Scholars, told Turkey's Anatolia news agency. "We don't see hope because the occupation is continuing."

U.S. officials had hoped the new Cabinet approved Thursday would help dent support for the militants within the Sunni Arab minority that dominated under ousted leader Saddam Hussein and is now believed to be driving the insurgency. However, the lineup excludes Sunnis from meaningful positions and leaves the key defense ministry in temporary hands.

"You, Bush, we will not rest until we avenge our dignity," al-Zarqawi said in the audiotape that was posted on the Internet. "We will not rest while your army is here as long as there is a pulse in our veins." He threatened more attacks against U.S. forces and warned against collaborating with Americans.

In Washington, an intelligence official said the tape appeared to be genuine.