AT LEAST 18 Shiite pilgrims were killed when a car bomb exploded in Baghdad.
The pilgrims were commemorating the anniversary of the death of a revered imam, officials said.
Shortly after the explosion, the Sunni extremist Islamic State group claimed responsibility for the attack in an online statement. It said the assault was carried out by a suicide bomber, but Iraqi officials denied that.
IS militants frequently target commercial areas and public spaces in mainly Shiite towns and districts.
According to an Iraqi police officer, the car was parked in Baghdad's southwestern Saydiyah district and blew up shortly after midday. The explosion killed at least 18 and wounded 45 people, the officer said.
Tens of thousands of Shiite faithful have been making their way this week to the northern Baghdad district of Kadhimiyah, where the 8th century Imam Moussa al-Kadhim is buried.
Security forces have blocked major roads in Baghdad in anticipation of attacks against pilgrims who traditionally travel on foot from different parts of Iraq.
Monday's attack came a day after two car bombs in the southern Iraqi city of Samawah killed at least 31 people and wounded 52, an attack that was also claimed by the Islamic State.
The annual Shiite pilgrimage prompted anti-government protesters on Sunday to disband their demonstration – at least temporarily – in Baghdad's heavily fortified Green Zone that they had stormed a day earlier.
While IS has suffered a number of territorial defeats in the past year, the group still controls significant stretches of territory in Iraq's north and west, including the country's second largest city of Mosul, estimated to still be home to more than 1 million civilians. Militants have recently increased attacks inside Baghdad in what officials say is an attempt to distract from their recent battlefield defeats.
