Several early-morning car bombings shook the Iraqi capital of Baghdad, killing as many as 26 people. The attacks were carried out by insurgents and al-Qaida-related terrorists eager to derail Iraqi elections set to take place on January 30.

The first bombing of the day, near the Australian embassy, was the largest.

At about seven o'clock local time, a thunderous boom rocked the Jadriyah district of Baghdad where the embassy is located. Powerful shock waves followed the explosion, blowing out hundreds of windows and several dozen doors in nearby buildings.

Thick clouds of black smoke filled the sky and the remains of a truck bomb could be seen burning in front of a military barracks used by the Australians.

U.S. troops and Iraqi police arrived and quickly sealed off the area. Fearing a second attack, the police warned residents and journalists living in a nearby hotel not to gather outside or on rooftops to view the destruction.

The U.S. military says the blast killed two Iraqis and wounded several people, including two Australian soldiers. It was not immediately clear if the explosive-laden truck was remotely detonated or driven by a suicide bomber.

Thirty minutes after the bombing in Jadriyah district, another powerful explosion awoke residents in eastern Baghdad. A car bomb blew apart at a police station next to a hospital, killing at least half a dozen policemen.

The U.S. military says a third car bomb detonated at about 45 minutes later, at an undisclosed location southwest of the Baghdad International Airport. That blast killed two Iraqi security guards.

The fourth attack came 15 minutes later, near a checkpoint at an abandoned airfield. Two Iraqi army soldiers and two civilians died in the car bombing there.

Hours later, another car bomb exploded in northern Baghdad near a bank and a Shiite mosque, killing at least one person.

U.S. and Iraqi officials have warned of a steady increase in violence leading up to elections on January 30, in which Iraqis will choose a new national assembly and provincial legislatures. Sunni Muslim insurgents and foreign terrorists, who oppose the polls, have warned Iraqis to boycott the elections or face attacks.

On Tuesday, Iraq's Interior Ministry announced a security clampdown before the balloting. The ministry says it plans to, among other things, close Iraq's borders for three days during the election period and impose travel restrictions.

Despite the daily violence and calls from some Sunni Muslim leaders to delay the voting, the U.S. ambassador to Iraq, John Negroponte, told reporters Tuesday that the elections will take place, no matter how hard insurgents try to derail them.

"The die is absolutely cast there. The election is going forward," he said. "It is going to happen on the 30 of January. And I think these various elements would do well to reflect on that fact and start thinking of how they are going to participate in designing the political future of their country."

Late Wednesday, the terrorist organization al-Qaida in Iraq, led by Jordanian Islamic militant Abu Musab al-Zarqawi, claimed responsibility for the truck bombing near the Australian embassy.

The al-Zarqawi group, which recently allied itself with Osama bin Laden's terror network, is believed to have carried out scores of deadly car bombings and kidnappings in Iraq since mid-2003. As deadly as the group has been, U.S. commanders say they believe al-Qaida in Iraq is playing only a small part in the Sunni insurgency in Iraq.