A torrent of bombings and shootings ripped across eight Iraqi cities today targeting police and Shiite pilgrims and killing 46 people.
The deadly wave undermined the government's hopes for stability ahead of next week's meeting of the Arab world's top leaders.
The Iraqi wing of al Qaida said it was behind at least one of the attacks near Baghdad's heavily guarded Green Zone. A statement on a militant website said the group targeted the office that will oversee security for the upcoming Arab League summit - the first time the meeting is set to be held in Baghdad for more than a generation.
Authorities have feared al Qaida or its Sunni sympathisers would try to strike at this year's Arab League summit. Plans for Baghdad to host the meeting last year were postponed, in part because of concerns about Iraq's security.
In all, eight cities were hit in what appeared to be coordinated attacks against police and government officials. More than 200 people were wounded in a gloomy reminder of the violence that has sown chaos across Iraq since the invasion nine years ago.
One of the deadliest strikes came in the Shiite holy city of Karbala, where two car bombs exploded in a crowded shopping and restaurant area. Thirteen people were killed and another 50 were wounded.
Five Iranian pilgrims were among the dead. Located 50 miles south of Baghdad, Karbala is a destination for thousands of Shiite pilgrims from around the world who visit the golden shrines of two revered imams each day.
The wave of violence began after dawn Tuesday.
Militants blew up the house of a police official in the western city of Fallujah, planted bombs near the fortified Green Zone and shot up a security checkpoint in Baghdad, set off an explosion at a police station in the northern city of Kirkuk and attacked restaurants and shopping areas in two southern towns.
Thirteen people, most of them policemen, were killed in Kirkuk and another 59 wounded.
Officials have been bracing for attacks in the run-up to the Arab League summit during which the Shiite-led government hopes to showcase Iraq's improved security and stability since the sectarian fighting a few years ago that almost pulled the country into civil war.
Insurgents are seeking to belie Baghdad's better image, and officials expect more attacks as hundreds of dignitaries and journalists converge on the capital next week.
Two of the attacks Tuesday hit right outside the Green Zone where the summit will be held.
Last week, the government said Iraq would deploy an unprecedented number of security forces to protect the capital for the summit. An estimated 26,000 police and soldiers - including more than 4,000 from Iraq's north and south - are expected to be deployed in Baghdad.
But citizens and politicians have questioned whether Baghdad would be safe during the Arab meeting.
Extremists have launched large-scale attacks in Iraq every few weeks for nearly a year. The violence now is nowhere as frequent as it was during the tit-for-tat sectarian fighting a few years ago. But the attacks appear to be more deadly than they were before American military's withdrawal in late December.
The last widespread wave of attacks across Iraq, on February 23, killed 55 people and wounded more than 225.