At least 22 people have been killed as insurgents unleashed a string of bomb attacks across Iraq, mainly targeting Shiite Muslim pilgrims, extending a wave of deadly bloodshed into a second day.
The eruption of violence follows nearly two weeks of relative calm, and threatens to inflame rising tensions among Iraq's ethnic and sectarian groups.
The worst attack took place near Dujail, 50 miles north of Baghdad, where two car bombs exploded near pilgrims who were travelling on foot to a shrine in the town of Samarra.
The head of the Salahuddin provincial health directorate, Raed Ibrahim, said 11 people were killed and more than 60 injured in that attack.
"We heard thunderous explosions, and everybody went outside and saw burning cars and several bodies on the ground. Market stalls on both sides of the road were on fire," said Naseer Hadi, who works in the Dujail post office.
The pilgrims were heading to Samarra to commemorate the death of two prominent Shiite Imams who are buried in the al-Askari shrine there.
A 2006 bombing at the gold-domed shrine that was blamed on al Qaida in Iraq set off years of retaliatory bloodshed between Sunni and Shiite extremists which left thousands of Iraqis dead and pushed the country to the brink of civil war.
The attacks in Dujail came hours after a car bomb struck a bus carrying foreign pilgrims near the southern Shiite holy city of Karbala. Four people were killed and 12 wounded in that attack, according to police and hospital officials.
In the town of Qassim, 78 miles south of Baghdad, a parked car bomb exploded near a bus stop, killing five people and wounding 20. The casualties included Shiite pilgrims who were heading to Karbala, said police and hospital officials.
In north-eastern Baghdad, a roadside bomb apparently meant to hit an army patrol missed its target and struck a civilian car, killing two passengers and injuring two others, said police and hospital officials.