"The series of special invasions [was] launched, under the guidance of the Ministry of War in the Islamic State of Iraq, to support the weak Sunnis in the prisons of the apostates and to retaliate for the captives who were executed," the group posted on an al-Qaida Web site.
Explosives were detonated Thursday during the height of the morning rush hour, hitting a number of Baghdad's mixed Sunni-Shiite neighborhoods, CNN reported. Nine car bombs, six roadside bombs and a mortar round were exploded in a two-hour window in residential, commercial and government districts in the Iraqi capital, police said.
Recent political turmoil raised fears of a return of sectarian fighting evidenced at the height of the war several years ago. Last week, Maliki's domestic security forces accused Tariq al-Hashimi, Iraq's Sunni vice president, of running a hit squad, prompting him to flee. This week, Iraqi lawmakers with ties to rebel Shiite cleric Moqtada Sadr called for the country's parliament to be dissolved and for new elections within six months.