BAGHDAD, Iraq — At least 38 Iraqi civilians, security-force members and officials were killed yesterday in attacks that underscored the ruthlessness and randomness of much of the nation's violence.

The day's victims included 12 people killed when a suicide attacker drove a vehicle loaded with explosives into a restaurant near the northern city of Kirkuk.

In Baghdad, gunmen fired on a market area crowded with civilians, killing nine, the Defense Ministry said.

The U.S. military, meanwhile, said two U.S. soldiers were killed in combat near Ramadi and one died of nonbattle injuries in Kirkuk on Wednesday. At least 1,667 U.S. military members have died since the war began in March 2003, according to an Associated Press count.

Yesterday's violence demonstrated the ability of insurgents to keep up attacks despite a week-old security operation in Baghdad billed as the most aggressive yet by Iraq's new government, in office for less than two months.

The checkpoints and raids have brought all roads in and out of the capital under government control, said Interior Minister Bayan Jabr, who leads Iraq's police forces. Before the offensive, authorities controlled only eight of Baghdad's 23 entrances, he said.

The actions are meant to expose insurgent hide-outs in the city, he said, adding, "Within the next few months, we can deal with all of the killings and assassinations."

Jabr said security forces had detained 700 "terrorists" and killed 28 during the operation. The Defense Ministry said Wednesday that 680 people had been detained but that all but 95 had been released for lack of evidence.

Insurgent violence has killed 12,000 Iraqi civilians in the past 18 months, Jabr said yesterday, putting the first official count on the largest category of victims from bombings, ambushes and other increasingly deadly attacks.

The figure breaks down to an average of more than 20 civilians killed by bombings and other attacks each day. Authorities estimated that more than 10,500 of the victims were Shiite Muslims, based on the locations of the deaths, Jabr said.

Bombings and other insurgent strikes have killed thousands of Iraqi security-force members. No official totals have been released for those dead or for the total number of civilian casualties since the start of the war.

Jabr said the government figures showed that Shiites had suffered the bulk of insurgent attacks. No Sunni Muslim mosques, for example, had been destroyed by insurgents, he said.

Iraq's insurgency is led largely by members of the Sunni Arab minority that was toppled from power with Saddam Hussein. Foreign Arab fighters are largely blamed for the suicide bombings that claim most of the lives.

Jabr denied the police operation in Baghdad was unduly focusing on Sunnis, saying many of the operation's commanders were Sunnis. He also said the new government was trying to reform the Interior Ministry, including expelling officials and officers found to have tortured detainees or others.

The day's violence included two car bombs near the northern oil city of Kirkuk. A bombing at a restaurant apparently targeted bodyguards of one of Iraq's deputy prime ministers, Rosh Nouri Shaways, said Col. Abbas Mohammed Amin, police chief of Tuz Khormato, where the attack occurred. Shaways was not present, but five of his guards and seven other people were killed.

Earlier in Kirkuk, a suicide car bomber trying to attack a convoy of civilian contract workers killed a boy and three other Iraqi bystanders and wounded 11 people.

Another suicide bomber killed four people and wounded four in Baqouba, about 35 miles northeast of Baghdad. Hours later, two parked motorcycles in Mosul rigged with bombs blew up near a coffee shop there, killing five Iraqis and wounding 13.

Two other attacks in the Baghdad area killed four people and injured three.

In Washington yesterday, Iraq's new government appealed to the Bush administration to take a more assertive role, particularly on four key political and military issues, according to Iraqi and U.S. officials.

In talks with Vice President Dick Cheney yesterday and Secretary of State Condoleezza Rice on Wednesday, Foreign Minister Hoshyar Zebari requested greater U.S. and coalition help in crafting a new constitution. The deadline is less than three months away but deliberations have slowed.

With time running out for writing the constitution and then holding elections in December for a permanent government, Zebari warned that the United States has withdrawn too much, endangering the long-term prospects for success.

Iraq's current interim government, which was elected in January but was unable to select a Cabinet and to take over until late April, asked Washington to help bring the Sunni minority into the political process. Zebari asked the administration to use its leverage with major Sunni leaders, such as Egypt's President Hosni Mubarak and Jordan's King Abdullah, to weigh in with Iraq's Sunni leaders to get them to end a virtual boycott of the political process.

Zebari also asked the United States for additional staff and resources to accelerate the creation of an Iraqi army and police force.

Finally, the Iraqi government asked Washington to speed up confirmation of its new ambassador to Iraq, Zalmay Khalilzad. Iraq has been without a top U.S. envoy since John Negroponte returned to Washington in mid-March to become the administration's new director of national intelligence.

Information on yesterday's attacks and Wednesday's U.S. military deaths was from The Associated Press. The Washington Post's Robin Wright reported on the developments in Washington.