A car bomb has killed at least 10 people in a vegetable market in the town of Hilla, south of the Iraqi capital Baghdad, police say.
More than 95 people died in a triple bomb attack in Balad
They say more than 30 others were injured in the attack in the mainly Shia town, which has been the scene of previous attacks by insurgents.
The bombing came as the death toll from Thursday's blasts in Balad rose to 95.
Shias have been the main target in a spike in violence ahead of the 15 October referendum on the constitution.
Although it is Friday, the market in Hilla would have been busy when the bomb went off at around 0845 (0445GMT), says the BBC's Richard Galpin in Baghdad.
The Associated Press news agency described how emergency workers lifted the dead and injured into ambulances from streets around the market.
Hilla, some 60 miles (100km) south of Baghdad, has been the scene of the some of the biggest attacks in the insurgency over the past two years.
Almost 100 people died in a suicide bomb attack that also detonated a fuel tanker in the town centre in July, and more than 120 were killed in a suicide car bombing at the start of the year.
Late on Thursday, the market place in Balad, some 50 miles (80km) north of the capital, was hit by three near-simultaneous car bombings.
At least 95 people were killed and more than 100 wounded.
US helicopters ferried some to a nearby military base for treatment to help stretched emergency workers.
US President George W Bush warned earlier this week that insurgents were likely to step up their attacks ahead of the October referendum on the constitution.
"We can expect they'll do everything in their power to try to stop the march of freedom," he said.
Sunnis are unhappy with the constitution, which they say favours the majority Shia and Kurd communities, and could throw it out in the upcoming referendum.
The BBC's Middle East Editor, Jeremy Bowen, says the mainly-Sunni insurgents will do all they can to destroy the political option and hope that the killing drives Iraqis apart faster than politicians can bring them together.