Roadside bombs killed the Shiite mayor of a town in a volatile area south of Baghdad and an anti-Al Qaeda Sunni sheik north of the capital, police officials said.

Car bombs, meanwhile, struck Iraqi civilians in Baghdad and the northern city of Tal Afar as at least 21 other people were killed or found dead nationwide.

The mayor of Iskandariyah, 30 miles south of Baghdad, was killed along with four of his bodyguards as he headed to work, a police officer said. Another guard was wounded when the bomb struck the convoy of Mayor Abbas Hassan Hamza, a member of Prime Minister Nouri al-Maliki's Dawa Party, the official said.

Sheik Muawiya Naji Jbara, the head of the Salahuddin Tribal Awakening Council, died from head injuries he suffered after a roadside bomb exploded as his convoy traveled near Samarra, 60 miles north of Baghdad, his brother said, adding two guards also were wounded.

The blast occurred as the prominent Sunni sheik was traveling to an area southwest of Samarra to support the anti-Al Qaeda fighters there, a day after 16 members of the council were wounded during clashes with gunmen, said his brother, Marwan Jbara.

The deadliest car bombing occurred about 7:15 a.m. near a line of vehicles waiting to fill up at a gas station in the predominantly Shiite neighborhood of Zafaraniyah in southeastern Baghdad. Police said at least four people were killed and eight wounded.

Another explosives-laden car blew up elsewhere in eastern Baghdad, killing at least two people and wounding 11 in a shopping district specializing in spare parts in the Camp Sara neighborhood, which is mainly Christian, police said.

North of the capital, a parked car left by a man and a woman pretending to be shoppers exploded near a market in Tal Afar, killing at least three civilians and wounding 30, according to the top city official Maj. Gen. Najam Abdullah.

Nobody claimed responsibility for the attacks but they come at a time when an Al Qaeda front group has threatened to step up violence during the Islamic holy month of Ramadan.

All the police officials gave details about the violence on condition of anonymity because they feared retribution.

Wednesday's attack against the Polish ambassador — apparently well planned in one of Baghdad's most secure neighborhoods — raised questions about whether it sought to punish Poland for its contributions to the U.S.-led military force in Iraq. But Poland's prime minister, Jaroslaw Kaczynski, said his nation would not retreat "in the face of terrorists."

The Iraqi foreign ministry denounced the attack, calling it a cowardly "criminal assassination attempt" aimed at "damaging the strong relations between Iraq and Poland."

The diplomatic convoy was hit by three bombs and then attackers opened fire in the Shiite-controlled Karradah district. Polish guards returned fire as the injured ambassador, Gen. Edward Pietrzyk, was pulled from his burning vehicle. At least 10 people, including four Polish security agents, were wounded.

U.S. Embassy officials dispatched Blackwater helicopters to evacuate the ambassador and others. Blackwater was not involved in protecting the Polish convoy.

Pietrzyk, who was commander of ground forces in Poland before taking the ambassador post in April, suffered minor burns over 20 percent of his body, including his head and right arm and leg, said Polish Charge d'Affaires Waldemar Figaj.

"They were waiting for us," Figaj told The Associated Press as he gave details of the attack.

Poland, a staunch U.S. ally, contributed combat troops to the 2003 U.S.-led invasion and has since led a multinational division south of Baghdad. About 900 Polish troops remain in the country training Iraqi personnel; 21 Poles have died during the conflict.

Last year, the Polish government extended its mission in Iraq until the end of 2007, but has made no decision on next year.

In another development, U.S. and Iraqi troops detained a lawmaker from Iraq's biggest Sunni bloc after he allegedly attended a meeting of suspected Al Qaeda in Iraq fighters.

Naif Jassim Mohammed was taken into custody Wednesday during a funeral for one of his neighbor's in Shurqat, about 140 miles north of Baghdad, according to Salim Abdullah, a spokesman for the Iraq Accordance Front, an alliance of three parties that have 44 of parliament's 275 seats. He said he didn't know why Mohammed was arrested.

The U.S. military said American and Iraqi troops acting on a tip seized a member of parliament on Sept. 29, but it did not identify the man other than to say he was a "suspected criminal leader."

He was being held for questioning "after being found at a suspected Al Qaeda in Iraq meeting," according to a statement.

Lt. Justin Cole, a U.S. military spokesman in Baghdad, said he had no information about a similar raid in Shurqat late Wednesday, and the different time elements could not immediately be reconciled.

The man remained in custody Thursday and officials are reviewing the case, the U.S. military said.