BAGHDAD -- Car bombs and attacks in cities across Iraq -- including two blasts at a checkpoint at Baghdad’s international airport -- killed at least 20 people and wounded more than 200 on Monday, police said.

The wave of attacks in Baghdad, Kirkuk, Tuz Khurmato and other towns came just days before Iraqis vote in provincial elections that will test political stability more than a year after U.S. troops left the country.

No one claimed responsibility for Monday's bombings, but al Qaeda's local wing, the Islamic State of Iraq, and other Sunni Islamist groups have vowed to wage a campaign against Shiites and the government to stoke sectarian confrontation.

Ako Rasheed / Reuters

Iraq was hit by a wave of attacks on Monday, including a bomb blast in Kirkuk, 155 miles north of Baghdad.

Two people were killed by car bombs that exploded at a Baghdad airport checkpoint, police sources said.

Attacks on the heavily guarded airport and the fortified International Zone housing many embassies are rare, but insurgents have stepped up bombings this year.

"Two vehicles managed to reach the entrance of Baghdad airport and were left parked there. While we were doing routine searches, the two cars exploded seconds apart. Two passengers travelling to the airport were killed," a police source said.

The most deadly attack was in Tuz Khurmato, 105 miles north of Baghdad, where four bombs targeting police patrols killed five people and wounded 67, officials said.

Iraqis vote on Saturday for members of provincial councils in a ballot that will test Shiite Prime Minister Nuri al-Maliki's political muscle against Shiite and Sunni rivals before a parliamentary election in 2014.

Ten years after the U.S.-led invasion of Iraq, al Qaeda is regaining ground, especially in the western desert close to Syria's border. Islamic State of Iraq says it has joined forces with al-Nusra Front rebels fighting in Syria.

Sunni insurgents, especially al Qaeda, see Baghdad's Shiite-led government as oppressors of the country's Sunni minority and see Shiites in general as apostates from true Islam.

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Emad Matti / AP

People react at the scene of a bomb attack in Kirkuk, Iraq on Nov. 27, 2012. Three parked car bombs exploded Tuesday morning simultaneously in the city of Kirkuk, home to a combustible mix of Kurds, Sunni Arabs and Turkomen who all claim rights to the city, police said.

Ako Rasheed / Reuters

A Kurdish security officer stands guard next to the destroyed headquarters of the Kurdistan Democratic Party (PDK) after a bomb attack in Kirkuk on Nov. 27, 2012.

Reuters reports — Bombs targeting ethnic Kurds killed four people on Tuesday in the city of Kirkuk in Iraq's disputed northern territories, where the Iraqi army and troops from the autonomous Kurdistan region have been in stand-off for more than a week.

It was not immediately clear who was behind the attacks although Sunni Islamist insurgents including a local affiliate of al Qaeda continue to strike regularly, killing 144 people across Iraq in October alone.

After decades of oppression, Kurds in Syria get taste of freedom

The latest bomb attacks come after troops from Baghdad and the Kurdistan region moved in last week on the territories over which both the central government and the Kurds claim jurisdiction. Read the full story.

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