Suicide bombers have set off a wave of blasts in Iraq, killing at least 71 people and injuring more than 100 in the bloodiest day since February.
An Iraqi man grieves for his brother after the Tikrit attack
The deadliest bombings were in Tikrit, where at least 33 died, and the town of Hawija, where at least 32 were killed.
Suicide bombings and shootings rocked Baghdad, killing at least four people.
The attacks continue an upsurge in violence that has claimed more than 400 lives since the start of May, as US forces fight rebels in the west.
Laith Kubba, an Iraqi government spokesman, told the BBC that rebels were lashing out wildly, knowing their "days are numbered".
But the insurgency appears to be gathering pace rather than running out of steam, the BBC's Jim Muir in Baghdad says.
The attacks came a day after the US Senate unanimously approved an emergency spending bill authorising a further $82bn for US military operations in Iraq and Afghanistan, among other activities.
Wednesday's wave of bombings began in the northern city of Tikrit - Saddam Hussein's hometown, which is dominated by Iraq's minority Sunni Muslim community.
At least 33 people were killed and about 70 injured in a car bombing in a crowded marketplace, police said.
The bomber had apparently been targeting a police station, but police forced him to swerve into the market.
Almost all the dead are said to be Shia Muslim civilians who had gathered to look for work.
Ibrahim Mohammad, a migrant worker who saw the explosion, called it "a tragedy", Reuters news agency reported.
"Some [bodies] were burned, some were ripped to pieces."
The militant group Ansar al-Sunna claimed responsibility for the Tikrit attack, saying it was aimed at migrant workers employed by a nearby US base.
Baghdad saw suicide car bombings and an attack on a convoy
At least 32 people were killed and dozens wounded soon afterwards, when a suicide bomber with explosives strapped to his body hit a police and army recruitment centre in the northern town of Hawija.
The bomber reportedly mingled with recruits before setting off his explosives, a tactic that has been used at least twice before in recent weeks, our correspondent says.
"I was standing near the centre and all of a sudden it turned into a scene of dead bodies and pools of blood," police Sgt Khalaf Abbas told the Associated Press news agency by telephone.
"Windows were blown out in nearby houses, leaving the street covered by glass."
Some casualties were taken to Kirkuk, the nearest city, because Hawija does not have the means to care for them, AP reported.
There were also at least four explosions in Baghdad, including a suicide car bombing in the Dura district that killed three people other than the bomber and injured at least eight.
Baghdad was also the scene of an attack on a police patrol in the Mansour district that killed two policemen and a civilian, Reuters reported.
Governor of Anbar, Iraqi
Mohammad Jalal Saleh
Security chief, Iraqi
Marie Jeanne Ion, Sorin Dumitru Miscoci, Ovidiu Ohanesian
It was unclear if a third car bombing, and a roadside bomb aimed at a US convoy, caused any deaths.
Not since 28 February - when 125 people died in a massive car bombing in Hilla - have insurgents killed so many Iraqis in a single day.
US forces have been mounting a major counter-insurgency operation in the western province of Anbar, where they say they have killed about 100 rebels in the past several days.
The insurgents deny suffering such heavy losses.
The governor of Anbar was kidnapped on Tuesday and rebels have demanded that the US stop its operations.
A number of foreigners are also being held hostage - among them an Australian engineer seized in Baghdad in late April and a Japanese security contractor captured on Sunday.