Insurgents detonated a suicide truck bomb outside Australia's embassy in Baghdad yesterday and hit Iraqi security targets with at least three car bombs, killing 26 less than two weeks before January 30 elections.

The deadliest attack was a blast near a police headquarters and hospital in eastern Baghdad. The US military said the bomb killed 18 people, including five Iraqi police, and wounded 21.

Half an hour earlier a suicide truck bomb rammed into the security barriers outside the Australian embassy, witnesses said. Two Iraqis were killed and two Australian soldiers were among several people wounded, officials said.

A third vehicle bomb killed two Iraqi security guards near Baghdad's international airport and a fourth bomb killed two civilians and two Iraqi soldiers at a military complex in Baghdad, the US military said.

A police source said another bomb exploded at a Baghdad bank, targeting police as they collected their salaries. Witnesses said at least one person was killed.

Australian ambassador Howard Brown said the truck bomb that exploded near his embassy was close to accommodation for diplomatic security personnel. "It was a car bomb aimed at the building where the security people are based. It was quite a substantial explosion," he said.

The al Qaeda-linked insurgent group led by Jordanian militant Abu Musab al-Zarqawi said it had carried out three suicide bombings in Baghdad, including the Australian embassy.

Insurgents have repeatedly targeted Iraqi soldiers and police in the run-up to the elections. Iraqi forces are due to provide protection at polling stations on election day. Militants posted yesterday an Internet video showing the killing of two Iraqis who were working for a US communications firm involved in the country's election.