Updated at 3:18 p.m. ET: At least 52 people were killed and 250 wounded as car and roadside bombs exploded in at least 12 cities and towns across Iraq Tuesday, police and hospital sources said, extending a spate of violence ahead of next week's Arab League summit in Baghdad.

The meeting is seen as the country's debut on the regional stage following the withdrawal of U.S. troops in December and Iraq's government is anxious to show it can reinforce security to host its neighbors. Tuesday is the ninth anniversary of the U.S.-led invasion.

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The AFP news agency reported that while violence in Iraq was down from the peak in 2006 and 2007, a total of 150 Iraqis were killed last month.

The deadliest attack on Tuesday occurred in the southern Shiite Muslim holy city of Kerbala, where twin explosions killed 13 people and wounded 48, according to Jamal Mahdi, a Kerbala health department spokesman.

"The second explosion caused the biggest destruction. I saw body parts, fingers, hands thrown on the road," 23-year-old shop owner Murtadha Ali Kadhim told Reuters.

"The security forces are stupid because they always gather at the site of an explosion and then a second explosion occurs. They become a target," he added.

Iraqis worried
Security forces are frequently targeted in Iraq, where bombings and shootings still occur on a daily basis and Sunni Muslim insurgents and Shiite militias are still capable of carrying out lethal attacks.

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Many Iraqis worry whether their government has the wherewithal to impose security on the country.

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In the northern city of Kirkuk, a car bomb exploded near a police headquarters, killing seven people and wounding 30, police and health sources said, while a suicide car bomber killed three and wounded 21 in central Baghdad.

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A car bomb targeting a police patrol in Mahmudiya in the south killed three people and wounded 12, while a car bomb blast near a convoy carrying the governor of Anbar province killed one of his security men and wounded eight other people.

Blasts also occurred in Baiji, Samarra, Tuz Khurmato, Daquq and Dhuluiya, all north of Baghdad, and Hilla and Latifiya in the south. Police in the northeastern city of Baquba said they had also found and defused eight bombs.

The Arab League summit is due to be held in Baghdad on March 27-29, the first time Iraq will host the event in more than 20 years.

Reuters contributed to this report.

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