BAGHDAD, Iraq — Gunmen killed at least 24 police, soldiers and government workers in Iraq yesterday, and an Iraqi general said about 50 suspected insurgents were captured in the first days of a new security operation in Baghdad.

Early today, gunmen in two cars attacked a minibus bringing workers to a U.S. base, killing 13 people, a police source said. The minibus driver and nine workers from the base were killed in the attack in Baqouba, just north of the capital, after the gunmen blocked the bus and opened fire.

Three other civilians died when the bus careered into their car, the Baqouba police source told Reuters news service.

The latest bloodshed occurred in a series of small-scale ambushes and shootings, as Baghdad received a respite yesterday from the wave of suicide bombings that killed 22 people in the embattled capital the day before.

However, a car bomb targeted U.S. and Iraqi troops in Rawah, 175 miles northwest of Baghdad, witnesses reported. At least one person, believed to have been a civilian, was killed, the witnesses said.

The deadliest attack yesterday was in the western Baghdad district of Khadra, where eight policemen died in a gunbattle with insurgents, police said. It was unclear if the insurgents suffered casualties.

Gunmen also killed at least five other police officers, including a colonel, in attacks around the capital, police and hospital officials said. Three civilian government employees were killed in separate ambushes in Baghdad, police reported.

A policeman died in a shootout between insurgents and security forces just north of Baghdad in Taji, police said. And in Samarra, 60 miles north of Baghdad, gunmen killed a police colonel, an Interior Ministry official and three Iraqi soldiers in a series of attacks.

In the north, gunmen killed two Iraqi soldiers in eastern Mosul and assassinated Abdul-Ghani al-Naimi, whose brother is a member of the Iraqi parliament.

Also yesterday, the military said a U.S. Marine died in a nonhostile incident Sunday at a U.S. base in Ramadi. At least 1,766 members of the U.S. military have died since the beginning of the Iraq war in March 2003, according to an Associated Press count.

The violence came as Iraqi forces reported a new offensive against the insurgents in Baghdad. An Iraqi general, who spoke on condition of anonymity for security reasons, said the latest operation began last week on the west side of the Tigris River, which divides the city.

He said about 50 suspected insurgents, including two Syrians, were captured in the opening days of the operation, which will be expanded over the next few days.

On a visit to Berlin, the chairman of the Joint Chiefs of Staff, Gen. Richard Myers, said a recent spike in suicide bombings wouldn't derail the drafting of a constitution or progress toward democracy. But he warned of more violence ahead.

Al-Qaida in Iraq reported yesterday that one of its "field commanders" had been killed by coalition forces in western Iraq, the terror group purportedly said in a statement posted on a Web site used by militants. The statement did not say when the man, Abi Salih al-Ansar, was killed.

Security has deteriorated steadily since Prime Minister Ibrahim al-Jaafari announced his Shiite-dominated government April 28.

The deteriorating security situation has alarmed Iraq's most powerful Shiite clergyman, Grand Ayatollah Ali al-Sistani, whose tacit endorsement was crucial in the Shiite victory in the Jan. 30 elections.