Suicide bombers and gunmen tried to storm an army base in Baghdad on Sunday, killing at least seven people and wounding 22 less than a week after Washington declared US combat operations in Iraq over, officials said.

Insurgents are targeting Iraqi police and troops as the US military gradually pulls out, while the failure of Iraq's political leaders six months after an election to agree on a new government has also stoked tensions.

Sunday's attack took place in broad daylight, just over two weeks after dozens of Iraqi army recruits and soldiers were killed by another suicide bomber at the same base.

A police source said seven soldiers were killed and 22 wounded in at least two explosions. An Interior Ministry source said seven people were killed and 21 wounded in the attack, of which 4 of the dead and 15 of the wounded were soldiers.

The Interior Ministry source said gunmen opened fire on the entrance of the army base, then two suicide bombers on foot tried to storm the gate but were stopped and killed. A third suicide bomber on foot was shot and injured, the source said.

Baghdad security spokesman Major General Qassim al-Moussawi and a federal police official said the attack also involved at least one suicide bomber in a car. Moussawi put the death toll at two, with eight people wounded.

'It was a suicide car bomber targeting the main entrance of Rusafa military command,' Moussawi said. 'There are bodies and body parts but we don't know if they belong to attackers or civilians,' he added.

Residents in the neighbourhood reported extensive shooting after the explosion and said the gunfire continued for more than an hour after the attack.-Reuters