Iraqi security officers at the site of the blast
Iraq's al Qaeda affiliate has claimed responsibility for a wave of attacks across the country in June and July it said were part of a new offensive against the Shi'ite-led government.
Once at the heart of the insurgency against U.S. troops in Iraq, al Qaeda now targets mainly Shi'ites and local security forces in an attempt to stir up the kind of sectarian tensions that drove Iraq to the edge of civil war four years ago, reports Reuters.
Though weakened by years of fighting American and Iraqi forces, security experts say the al Qaeda wing has gained new life from the Syrian turmoil next door, which is drawing funds and Sunni Islamist fighters to its cause.
Al Qaeda's local wing, the Islamic State of Iraq, said in a statement on a radical Islamist website the latest attacks were part of a new offensive declared by its leader, Abu Bakr al-Baghdadi, who has also threatened U.S. targets.
At the start of the month, two car bombs exploded near the Baghdad counter-terrorism unit holding al Qaeda prisoners, killing at least 19 people, before gunmen wearing suicide vests stormed the building to try and free fellow insurgents.
Only after a gun battle were security forces able to reclaim control of the building. All the gunmen were killed in the fighting, which Iraqi authorities blamed on al Qaeda.
"A group of believers from the Sunni people launched an operation targeting a building of the Safavid project and a pillar of its security in this country, the headquarters of the anti-terrorism directorate," the statement said.
Safavid is a reference to the ruling dynasty of Shi'ite Iran from the 16th to 18th centuries which at times also controlled parts of modern-day Iraq.