A homicide bomber wearing an Iraqi army uniform blew himself up Saturday on an Iraqi military base in Saddam Hussein's hometown of Tikrit, killing at least three Iraqi officers, officials said.

The dead included a lieutenant colonel, a major and a lieutenant, and wounded a lieutenant colonel at the base in western Tikrit, said Maj. Gen. Abdul-Aziz Mohammed Jassim, a spokesman for Iraq's Defense Ministry.

The bomber targeted a group of Iraqi army recruits who had just finished their training and were being dispatched to another area of Iraq, Jassim said.

The attack in a Sunni Arab city appeared to be part of a campaign by Sunni-led insurgents to discourage Sunnis from joining Iraqi security forces. The Bush administration hopes that newly trained Iraqi soldiers and police can one day improve security in Iraq enough to begin withdrawing U.S. forces from the country.

In other violence Saturday:

—Suspected insurgents kidnapped seven Iraqis, including three paramilitary policemen, near the town where a roadside bomb killed three U.S. service members the day before, police said.

—A roadside bomb hit an Iraqi police patrol in east Baghdad, killing one officer and wounding one, said police Lt. Bilal Ali. Such bombs have long been the most effective means of insurgent attacks on coalition forces.

—Two mortars were fired in northern Baghdad, one hitting a home and killing two children and wounding a woman, said police Maj. Moussa Abdul-Karim.

—Police in Baghdad also found the bodies of seven Iraqi men, five of them relatives from Iraq's Sunni Arab minority, who had been kidnapped and brutally killed. They appeared to be the latest victims of a wave of sectarian killings by "death squads," police said.

Saturday's kidnappings of the seven Iraqis occurred in and around Mahaweel, a city of Sunnis and Shiites about 35 miles south of Baghdad, police said.

In one, heavily armed insurgents stopped a car carrying three paramilitary policemen from Iraq's Interior Ministry to work and captured them, said police Capt. Muthana Khalid. Nearby, suspected militants stopped four minibuses that were driving toward a bus station to pick up passengers and kidnapped all four drivers, Khalid said.

On Friday, a roadside bomb targeting a U.S. military convoy had killed three soldiers in the same area, police said. The attack raised to at least 2,416 the number of U.S. military members who have died since the Iraq war started in March 2003, according to an Associated Press count.

As the violence continues, American officials hope that Iraq's new national unity government of Shiites, Sunnis and Kurds will eventually reduce sectarian tensions and lure disaffected Sunni Arabs away from the insurgency so U.S. and other foreign troops can begin to go home.

Prime Minister Nouri al-Maliki has until late this month to complete his Cabinet, the final stage in organizing the new government. Haitham al-Husseini, a Shiite spokesman, said the Cabinet would be announced Tuesday.

The statement was made after a meeting among al-Maliki, President Jalal Talabani, a Kurd, and two top Shiite leaders. No Sunni Arabs politicians attended, and it was unclear whether the Sunnis had accepted the Tuesday date.

In a joint interview Friday with Al-Arabiya television, Foreign Minister Hoshyar Zebari, a Kurd, and Sunni Arab lawmaker Saleh al-Mutlaq clashed over whether the Kurds should retain the Foreign Ministry post.

Zebari, who has headed the ministry since 2003, said the Kurds deserved the ministry "due to our long struggle" against Saddam Hussein's regime.

Al-Mutlaq described the talk of an impending Cabinet announcement "as a sword over our neck" and complained about the system of allocating top posts along religious or ethnic lines.