Militants unleashed a wave of attacks in Iraq on Thursday, mainly targeting Shiite areas in and around the capital of Baghdad, killing at least 50 people and wounding dozens, authorities said. The Islamic State group has overrun vast areas in western and northern Iraq as well as parts of neighboring Syria, and has vowed to destabilize and eventually take over Baghdad. It claimed responsibility for the day's deadliest strike. In that attack, two parked car bombs exploded simultaneously in a commercial area in the northern Dolaie neighborhood, killing 14 civilians and wounding 34 others, a police officer said.