Suicide truck bombers struck police checkpoints on two bridges in a Shia area south of Baghdad today, killing 22 people and wounding 60, police said.
A police source said five policemen were among the dead, but it was not clear how many casualties were caused by each blast.
Police said the first bomber damaged the old Diyala Bridge and a nearby police station. Minutes later, a few kilometres (miles) away, another attacker detonated his truck bomb on the new Diyala Bridge. There were no immediate reports of damage on that bridge.
The two bridges over the Diyala River, a tributary of the Tigris, are commonly used by Shia pilgrims on their way to the holy Shia cities of Najaf and Kerbala to the south.
Suspected al-Qaeda Sunni Arab militants have carried out a series of attacks on bridges in Baghdad in recent weeks. Iraqi and US forces have stepped up security on bridges.
Last month, a truck bomb destroyed the Sarafiya Bridge in Baghdad, sending several cars crashing into the Tigris. Days later a suicide car bomber blew himself up on a ramp leading to another bridge in Baghdad.
Politicians from both sides of the Shia-Sunni sectarian divide have accused insurgents of trying to split the capital of seven million people along sectarian lines.