BAGHDAD, Iraq – An emboldened Iraqi insurgency staged carefully coordinated dual bombings in Saddam Hussein’s hometown and a Shiite neighborhood of the capital yesterday, killing at least 21 people. Lawmakers loyal to the new prime minister said he was ready to announce a Cabinet that would exclude his interim predecessor, Ayad Allawi.

An American soldier was killed in a separate attack.

Prime Minister-designate Ibrahim al-Jaafari had decided, some members of his political bloc said, to shun further attempts to include members of the party headed by Mr. Allawi, the secular Shiite politician who had served as prime minister as the country prepared for elections January 30.

Members of Mr. Allawi’s Iraqi List, which controls 40 seats in the National Assembly, said his party had not been officially informed of the development. Allawi loyalists were bidding for at least four ministries, including a senior government post and a deputy premiership.

“I heard from the media, and some of the other assembly members told me about it,” lawmaker Hussein Shaalan told the Associated Press late yesterday. But he said the party would continue to support the government even if excluded from the Cabinet.

Mr. Al-Jaafari’s list could be put to parliament as early as today, some of his bloc said. Others indicated the Cabinet announcement would be made tomorrow. Many such forecasts have proven wrong so far.

Many Shiites have long resented the secular Mr. Allawi, accusing his outgoing administration of having included former members of Mr. Hussein’s Baath Party, which brutally repressed the majority Shiites and Kurds.

There had been intense pressure to end the political bickering after a marked recent uptick in insurgent violence that many in Iraq blamed on the continuing political turmoil nearly three months after the country’s historic January 30 elections.

Also Sunday, the American military said it had detained four more suspects in the downing of a civilian Mi-8 helicopter on Thursday. Ten suspects have been apprehended in all, the military said.

A vehicle packed with explosives was driven into a crowd gathered in front of an ice cream shop in Baghdad’s western al-Shoulah neighborhood yesterday, police Major Mousa Abdul Karim said. Minutes later, as police and residents rushed to help the victims, a second suicide car bomber plowed into the crowd. At least 15 people were killed and 40 wounded.

In Tikrit yesterday, two remotely detonated car bombs exploded in quick succession outside a police academy, killing at least six Iraqis and wounding 33, police and a hospital official said.

Insurgents also attacked American forces. A roadside bomb hit one convoy in eastern Baghdad, killing one American soldier and wounding two, the American military said. Iraqi police said two civilians also were wounded in the attack.

An American sailor was killed Saturday when the Marine convoy he was traveling with was hit by a roadside bomb in Fallujah, 40 miles west of Baghdad, the military said.

At least 1,568 members of the American military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

Al Qaeda in Iraq, the country’s most feared militant group, claimed responsibility for the Tikrit and eastern Baghdad attacks in statements posted on militant Web sites.

The group also claimed responsibility for a roadside bomb targeting a American patrol near the Abu Ghraib prison. The American military said no one was hurt in that attack.

South of the capital, three insurgents were killed yesterday as the roadside bomb they were trying to plant in the town of Mahawil exploded, said police in nearby Hillah.