Al Qaeda's affiliate in Iraq on Friday claimed responsibility for more than 20 bombings that hit cities and towns across the country the previous day, killing at least 36 and wounding almost 150.
In a statement posted on an Islamist website, the Islamic State of Iraq (ISI) group said it had carried out the attacks as a response to the campaign of detentions, torture, siege and confiscation of lands in Sunni areas, especially (in) Baghdad and its outskirts.
Thursday's attacks targeted towns and cities across Iraq, highlighting the threat al Qaeda and other militant groups continue to pose to security forces after the withdrawal of U.S. troops in mid-December.
ISI's statement threatened more attacks in the coming days.
Heightened tension between Shi'ites, Sunnis and Kurds in the coalition government since U.S. troops withdrew has raised fears of a return to sectarian violence of the kind that pushed Iraq to the brink of civil war in 2006-07.
The country is less violent than at the height of tensions then, but bombings and killings still occur daily, often aimed at Shi'ite areas and local security forces.
The ISI last month claimed responsibility for dozens of bombings that killed at least 52 people across the country ahead of an Arab League summit in Baghdad.
The ISI and Sunni Muslim insurgent groups say that they will not lay down their arms, despite the departure of U.S. forces, and will continue to battle the Shi'ite-led government.
(Reporting by Raheem Salman; Writing by Barry Malone; Editing by Andrew Osborn)