A suicide bomber detonated a car packed with explosives at an Iraqi army checkpoint north of Baghdad, killing at least three people, says police.
Police on Tuesday said the explosion is an apparent attempt to destabilise the Shiite-led government.
The blast in Taji, 20km north of the capital, followed another suicide attack in the same town a day earlier that killed at least 22 people.
It was the eighth suicide bombing in a month in Iraq, where insurgents are seeking to inflame tensions between Shiite, Sunni and ethnic Kurdish factions a year after US troops pulled out of the country.
"There were patches of blood, pieces of clothing and shoes scattered around the place," said policeperson Furat Fleh, whose patrol was near the checkpoint at the time of the blast. "We heard shooting and shouting after the explosion."
Prime Minister Nouri al-Maliki, a Shi'ite, has been struggling to quell mass protests by Sunni Muslims against what they see as the marginalisation of their sect since the fall of Saddam Hussein and the empowerment of Iraq's Shiite majority through the ballot box.
Ten years on from the US-led invasion of Iraq, sectarian and ethnic divisions run deep.
Violence has fallen from the height of inter-communal slaughter that killed tens of thousands in 2006 to 2007, but insurgents have still been carrying out at least one high-casualty attack a month since the US withdrawal in December 2011.
Amending anti-terrorism laws
Unrest in Iraq's Sunni heartland is compounding fears the war in neighbouring Syria – where Sunni rebels are fighting to topple a leader backed by Shiite Iran – could further upset Iraq's own delicate sectarian and ethnic balance.
Thousands of Sunni protesters have taken to the streets since late December, rallying mainly in the Sunni-dominated Anbar province where they have blocked a highway to Jordan and Syria.
Many demonstrators want the government to amend anti-terrorism laws that Sunnis believe authorities misuse to target them, but hardliners and Sunni Islamists have called for al-Maliki to step down and even for an autonomous Sunni fiefdom inside Iraq. – Reuters