BAGHDAD-The Islamic State group attacked a battalion of state-sponsored militia southeast of Tikrit on Friday, killing at least eight militia members, an intelligence official said.
IS claimed responsibility for the attack in a statement posted by its Aamaq news agency. The statement said IS fighters had struck the 9th Battalion of the Popular Mobilization Forces, "killing its commander and 13 soldiers."
The statement also said that IS fighters blew up the battalion's headquarters and other nearby positions and destroyed two Humvees that had arrived to assist the battalion.
The intelligence official spoke on condition of anonymity as he was not authorized to brief reporters.
The Popular Mobilization Forces are state-sponsored militias, largely comprised of Shiite Muslims, battling IS across the country.
Also on Friday, a police officer and medical sources said the death toll from a car bomb attack in a southern Baghdad neighborhood has reached 59 with 66 others injured.
Authorities initially said the Thursday night attack at an auto dealership in the al-Bayaa neighborhood killed at least 55 and wounded more than 60. The Islamic State group claimed credit for the bombing.
The police officer and medical personnel spoke on condition of anonymity because they were not authorized to brief reporters.
IS, in a statement early Friday, said its fighters detonated bombs in a parked car among a gathering of Shiites in the Fifth Police district Thursday. It did not give further details.
The extremist group has carried out near-daily attacks in Baghdad despite suffering military setbacks elsewhere in the country, including in the northern city of Mosul, where U.S.-backed Iraqi forces have been waging a major operation since October.
The spiritual leader of Iraq's Shiites Grand Ayatollah Ali al-Sistani, expressed his condolences for the victims' families and called on those "responsible for decision-making to recognize their responsibility to preserve security."
His comments were delivered at Friday prayers by his representative, Ahmed al-Safi, in the holy city of Karbala.
The U.S. State Department condemned the bombing, saying such attacks show the extremist group's "utter contempt for human life and its efforts to sow discord and division among the Iraqi people."
U.N. Deputy Spokesman for the Secretary-General Farhan Haq too condemned the attack in a statement issued Friday, which also conveyed "solidarity to the people of Iraq in resisting attempts to spread fear, intimidation and hatred."
Another four attacks in and around Baghdad on Thursday killed eight people and wounded around 30, authorities said.
The bomb attacks claimed by IS are seen as an attempt to distract attention as the militants cede territory along front lines in northern and western Iraq.
Elsewhere, Jaafar Husseine, spokesman for the Hezbollah Brigades, an Iraqi Shiite paramilitary group supported by Iran, said his brigade was fighting IS in the village of Ein Hasan west of Tal Afar in Nineveh province, 63 kilometers (39 miles) from Mosul. He said the unit had air support from the Iraqi army to thwart IS's attempt to open a passageway into neighboring Syria.