Fighting across Iraq between militants and US-led forces has left some 70 people dead, officials at the Iraqi health ministry have said.
Baghdad woke to explosions in its safest district
Baghdad saw some of the heaviest clashes for weeks as mortars fell in the Green Zone government quarter, and US helicopters fired missiles.
More than 30 people died during hours of gun battles on Sunday.
Meanwhile, US Secretary of State Colin Powell said US and Iraqi forces would eventually end the insurgency.
"This is a difficult time as this insurgency still rages and as we work to bring it under control. But it will be brought under control," he told NBC television.
As well as in Baghdad, clashes erupted in the west, north and south areas.
In Ramadi, west of the capital, 10 people died in clashes between Iraqi fighters and US soldiers.
The BBC's Caroline Hawley, in Baghdad, says that more than two months into the handover of power, neither Iraqi nor US forces seem able to exert control in the capital.
Rockets and mortar bombs began hitting the Green Zone early on Sunday morning.
Iraqis waved a militant banner over a burning US tank
The huge government compound, which also houses the US embassy, was bombarded by insurgents who oppose the presence in the country of US troops.
One blast hit the French embassy's car park, but caused no injuries. Another fell just short of the main international hotels.
Gun battles raged in Haifa Street, a stronghold of Saddam loyalists. Fighting broke out at around 0500 (0100 GMT) in the area on the western side of the Tigris River.
A US armoured vehicle caught fire and its four crew members were evacuated with minor injuries.
An American helicopter gunship opened fire with missiles and machine-guns at a crowd swarming around the vehicle who were cheering and throwing stones.
Two children and a journalist for an Arabic TV news channel, al-Arabiyya, were among those killed.
In other violence:
- An apparent suicide attack on Abu Ghraib jail, outside Baghdad, was foiled when guards shot at a vehicle which then exploded, killing the driver
- A car bomb in western Baghdad killed two police officers and a young boy
- Three Iraqi national guardsmen were killed around the town of Hilla, south of Baghdad. Three Polish soldiers died in an ambush in the same area
Meanwhile, Mr Powell said that the US was committed to giving the country stability.
And he added that he was confident that the elections for next year could still be held on time - though he gave no further details on the plan to end the violence.
"This is not the time to get weak in the knees or faint about it, but to drive on and finish the work that we started," he told NBC television.