BAGHDAD -- A series of car bomb attacks in Iraq's capital killed 38 people in Shiite areas Saturday, authorities said, after Islamic militants killed a journalist working for a local television network in a Sunni province.
The attacks come as Iraq faces its greatest challenge since the 2011 withdraw of U.S. troops, as militants from the Islamic State group now hold vast swaths of the country and neighboring Syria.
Police officials said the first bombing happened Saturday night when a suicide bomber rammed his explosive-laden car into a security checkpoint in Baghdad's northern district of Khazimiyah, killing 13 people, including three police officers, and wounding 28.
The second car bombing, targeting a commercial street in Shula district in northwestern Baghdad, killed seven people and wounded 18, police said. The blast damaged several shops and cars.
Also in Shula, police said a suicide car bomb attack on a security checkpoint killed 18 people and wounded dozens others.
Hospital officials confirmed the casualty figures for the attacks. All officials spoke on condition of anonymity because they were not authorized to brief journalists.
Nobody claimed responsibility for the attacks, yet Sunni insurgents frequently target Shiite population they deem as being heretics. That includes the Islamic State group, which now holds a third of the country in its sway. After a lightening offensive earlier this year.
Meanwhile, the U.S. military said Saturday it launched an airstrike north of the town of Tal Afar, hitting a small Islamic State fighting unit and destroying an armed vehicle. It said two other airstrikes northwest of Hit in Anbar province targeted two small militant units.
The U.S. military also said it conducted multiple airdrops Friday near the northern town of Beiji to resupply Iraqi security forces operating there. The airdrops delivered food and water, as well as 16,000 pounds of ammunition, the military said.
Also Saturday, the governor of Iraq's Salahuddin province said Islamic State group militants killed Raad al-Azzawi, who was a cameraman for Iraq's Salahuddin Television. Governor Raed Ibrahim said militants killed al-Azzawi on Friday in the city of Tikrit. Ibrahim said he wasn't able to provide any further details.
The Islamic State group has beheaded a number of journalists in Syria, saying the killings are in retaliation to U.S.-led coalition airstrikes in Iraq and Syria.
Reporters Without Borders said last month that the militants had threatened to kill al-Azzawi, a father of three, for refusing to join the Sunni militant group. The media watchdog said al-Azzawi was abducted on Sept. 7.