Three car bombs have exploded in mainly Shia areas of Baghdad, killing at least 67 people and injuring more than 120 despite a huge military offensive by US and Iraqi troops.
 
Sunday's blasts come just two days after Iraq's prime minister described Operation Imposing Law as a "brilliant success" as levels of violence in Baghdad appeared to fall.
 
US generals had cautioned the downturn might be temporary as fighters decided on their next move and adapted their tactics.
 
Hoda Abdel-Hamid, Al Jazeera's correspondent in Iraq, said that US and Iraqi officials have warned that the operation would take time to bear fruit.
 

"People here are expecting to see more attacks," she said.
 
Day of violence
 
First, twin car bombings in the main shopping centre of New Baghdad, a mainly Shia district in eastern Baghdad, killed 55 people and wounded 128, police said.
 
Shortly afterwards, a suicide car bomber rammed a police checkpoint in Sadr City, a stronghold of Shia leader Moqtada al-Sadr's Mahdi Army militia.
 
They are blamed by Sunni Arabi leaders and US officials for carrying out a large number of killings.
 
On Sunday, Tehran formally denied that al-Sadr was in Iran, rebuffing claims by Iraqi and US officials that he had left for the Islamic Republic.
 
Borders re-opened
 
Iraqi police had reported finding just five bodies in Baghdad on Saturday, a dramatic drop from the 40-50 they typically report.
 
It was one of the lowest tolls since the bombing of a Shia shrine in Samarra a year ago that intensified a wave of sectarian violence that has caused tens of thousands of deaths.
 
Before the blasts, Iraq had started to reopen its borders with Iran and Syria on Sunday as the operation appeared to bear fruit.
 
Trucks and cars began to flow over the Shalamchen border crossing between Iran and southern Iraq, three days after al-Maliki ordered the frontiers sealed as part of the security plan.

Photo caption

Smoke from New Baghdad district