Fifteen people were killed by six blasts in primarily Shia areas in Baghdad.
No group immediately claimed responsibility for the attacks, but Baghdad security chief Diya al-Wakil blamed Al-Qaeda, accusing the terror group of trying to create chaos.
"It's an attempt to cause our efforts to return security to the country to collapse," he told the Iraqi television. "It's a way to make the Iraqi people have a bad opinion about our work."
Violence has somewhat decreased since US troops pulled out of Iraq at the end of last year. But the bloody attacks raise fear of sectarian violence that could push the country toward civil war between the, Shia, Sunni and Kurd groups.
The latest attack was deadliest since 52 people died on 20 March when an Al-Qaeda-linked group claimed the killing of 52 people.