BAGHDAD - The Islamic State jihadist group has claimed responsibility for two car bomb attacks against Shiites in Baghdad, with Iraq under tight security Monday ahead of the annual Ashura commemorations.
A statement by IS posted on jihadist websites said "the heroes of Islam" detonated one car bomb in central Baghdad targeting Shiite security personnel and the other in the Shiite-majority Sadr City ara in the capital's north.
The two Sunday bombings killed at least 18 people and wounded dozens more, security and medical officials said.
A third blast struck near a tent in Al-Ilam where Shiites were distributing refreshments, killing at least 13 people, but the IS statement did not mention that attack.
"God permitted his servants the mujahedeen to break all of the alleged (security) plans of the Safavid government that they brag about in their media," the statement said, using a pejorative term for Shiites.
It said the bombings were carried out to coincide with "the greatest of their blasphemous seasons", a reference to Ashura, a Shiite commemoration that will peak on Tuesday.
Iraq has implemented heavy security measures involving tens of thousands of security forces members and allied militiamen to protect Shiites during Ashura.
Hundreds of thousands of Shiites will flock to the shrine city of Karbala south of Baghdad for Ashura, which marks the death of Imam Hussein, one of the most revered figures in Shiite Islam.
Ashura processions are also held in Baghdad and other parts of the country.
Shiites have been targeted during Ashura before, but this year's commemorations face even greater danger with IS in control of large areas of the country.
IS, like other Sunni extremist groups, considers Shiites to be heretics and frequently targets them with bombings.
Ashura is a major test for the new government headed by Prime Minister Haidar al-Abadi, as well as for Iraq's security forces, who have struggled to push the militants back.
A major attack during the commemorations in Karbala, where Imam Hussein is buried, would increase already significant tensions between Iraq's Shiite majority and Sunni Arab minority, and could spark revenge attacks.