A homicide car bomber slammed into an Iraqi police station northeast of Baghdad on Thursday, killing at least 13 people, police said.

Most of the victims were policemen and recruits lining up outside the station in Hibhib, the same small Sunni town near Baqouba where Al Qaeda in Iraq leader Abu Musab al-Zarqawi was killed in a U.S. airstrike more than a year ago. The area is considered a stronghold of both Al Qaeda-linked militants and Saddam Hussein loyalists.

Fifteen others were wounded in the attack, a police officer said on condition of anonymity because of security concerns.

The U.S. military announced three more soldier deaths: two killed in a mortar or rocket attack Tuesday, and another killed by a roadside bomb Wednesday.

At least 3,659 U.S. military personnel have died since the beginning of the Iraq war in March 2003, according to an Associated Press count. The figure includes seven military civilians.

Meanwhile, Prime Minister Nouri al-Maliki's party asked the country's largest Sunni Arab bloc to reconsider its withdrawal from the Cabinet in a last-ditch effort to restore the national unity government.

All six Cabinet ministers from the Iraqi Accordance Front quit the government on Wednesday to protest against what they called the prime minister's failure to respond to a set of demands.

Among them were the release of security detainees not charged with specific crimes, the disbanding of militias and the participation of all groups represented in the government in dealing with security issues.

Their resignation left only two Sunnis in the 40-member Cabinet, undermining efforts to pull together rival factions and pass reconciliation laws the U.S. considers crucial to heal the country's deep war wounds.

Al-Maliki's Islamic Dawa Party called Thursday on the Accordance Front to "reconsider its decision."

"The party expresses its concern and regret about this setback for Iraqi politics, an action taken before exploring any dialogue," a party statement said.

"We need to stand side by side as a national unity government and set aside all differences and cooperate in order to answer the challenges our people are suffering," it said.

An Accordance Front lawmaker, reacting to the Dawa statement, said Thursday that the bloc would reconsider its withdrawal only if promised "the priority of real partnership."

"If we were assured by tangible and concrete promises of real change ... and the priority of real partnership, we would reconsider our stance," Salim Abdullah, a Sunni parliament member, told The Associated Press. But he added that he was not optimistic such assurances would come from al-Maliki.

Iraqi President Jalal Talabani was scheduled to preside over a meeting later Thursday to try to jumpstart talks between the Accordance Front and the government, his office said.

Washington has been pushing al-Maliki's government to pass key laws — among them, measures to share national oil revenues and incorporate some ousted Baathists into mainstream politics. But the Sunni ministers' resignation from the Cabinet — not the parliament — foreshadowed even greater difficulty in building consensus when lawmakers return after a monthlong summer recess.

In a video conference late Wednesday, President Bush prodded al-Maliki to unite rival factions and show some overdue political progress, the White House said.

The two leaders spoke for 45 minutes on a secure video link, part of a regular series of conversations on the war and Iraq's struggling democracy.

"The president emphasized that the Iraqi people and the American people need to see action — not just words — but need to see action on the political front," White House press secretary Tony Snow said. "The prime minister agreed."

The Accordance Front has 44 of parliament's 275 seats, and those politicians will continue in the legislature. The withdrawal of its six Cabinet ministers from the 14-month-old government is the second such action by a faction of al-Maliki's coalition.

Five Cabinet ministers loyal to radical Shiite cleric Muqtada al-Sadr quit the government in April to protest al-Maliki's refusal to announce a timetable for the pullout of U.S. forces from Iraq.

Altogether at least 142 Iraqis were killed or found dead on Wednesday, including 70 who died in three separate bombings in Baghdad.

On Thursday, the U.S. military said American and Iraqi troops had killed seven suspects and captured 22 others in two days of raids across Iraq.

Among those targeted were emirs, or top-ranking figures, of Al Qaeda in Iraq, the U.S. military said. One emir was captured and another was killed Wednesday in separate operations in Mosul, it said. Another emir was captured a day later in Baghdad, it added.