At least 25 people were killed and dozens of others wounded after a truck bomb went off in a busy market in the central Iraq city of Diwaniya on Tuesday.
Some news agencies have put the death toll as high as 40.
The bombing occurred near a Shiite mosque where pilgims were gathering to set off on the 130-kilometer (80-mile) trip to the shrine city of Karbala. Police responded to the bombing by imposing a partial curfew and sealing off all entrances to the Diwaniya.
The attack came just hours after four people were killed and almost 30 others injured when two bombs went off in a vegetable market in Karbala.
There was no immediate claim of responsibility for Tuesday's bombings, but they appear to have targeted Shiites, government officials and security forces, all groups that militants linked to the al Qaeda terror network have been known to attack in the past.
Hundreds of thousands of Shiite pilgrims were expected to make the trip to Karbala this week for celebrations to mark the birthday of a key imam.
The bombings were just the latest in a series of such attacks in Iraq in recent weeks, which have raised fears that the county could be slipping back into a wider pattern of violence between Sunni and Shiite Muslims.
In June, no more than three days passed without a deadly attack.
pfd/ng (Reuters, AFP, AP)