A car bomb has killed at least 23 people near a Baghdad Shia mosque, exploding just before curfew and hours after other blasts killed 35.
Iraq has been hit by a wave of sectarian violence in the past week
In the bloodiest of the earlier attacks, 24 died when a bomber blew himself up near a petrol station in one of the Iraqi capital's Shia areas.
US President George W Bush has denounced the violence, saying Iraqis must choose either "chaos or unity".
The trial of Saddam Hussein meanwhile resumed after more than two weeks.
Prosecutors presented what they said were documents proving his involvement in the killing of more than 148 people from the Shia village of Dujail following an assassination attempt there in 1982.
In other developments:
- The bodies of nine Iraqis, including a Sunni Arab tribal leader, are found, riddled with bullets, in Tarfaya, south of Baquba
- Five defence ministry workers die when their convoy is hit by a roadside bomb in eastern Baghdad
- Two British soldiers are killed and another is injured by a roadside bomb on the outskirts of Amara, in the south
- A US soldier is killed by small-arms fire in the west of Baghdad
- A bomb damages a Sunni mosque erected by Saddam Hussein over his father's grave in his hometown of Tikrit.
The BBC's Jim Muir in Baghdad says the latest attacks are an apparently co-ordinated onslaught aimed at killing and injuring as many people as possible.
They come amid growing fears of a slide towards sectarian strife that has gathered momentum sharply since last week's attack on the Shia shrine in Samarra, he adds.
Decrying the upsurge in violence, President Bush said the perpetrators wanted to "destroy in order to create chaos".
The first car bomb exploded near a market and the Timimi mosque in the mainly Shia area of Karrada, killing six and wounding 18.
The market would have been fairly busy at the time, police said.
The eastern district of New Baghdad was rocked by two simultaneous explosions minutes afterwards.
A car bomb exploded near the main post office in a busy street, killing four and injuring 12.
Then a suicide bomber, who had strapped explosives to his body, blew himself up among a queue of people waiting for petrol nearby.
"If the government cannot do anything, let it step back - we have suffered enough," Firas Hassan Illiwi, who witnessed the attack, told Reuters news agency.
"Why does all this happen to us? Is it because we are Shia? Our crime is being Shia."
In the evening, a car bomb near a Shia mosque in the Hurriya area killed at least 23 people and injured at least 45.
On Tuesday, the Iraqi government said 379 people had been killed around the country and 458 injured in violence since the bombing of the Shia shrine in Samarra on 22 February.
It denied a Washington Post report saying that 1,300 people had died, quoting officials at the Baghdad morgue.