Iraq's government has declared a 60-day state of emergency in response to the escalation of violence by militants.
Violence in Iraq has escalated sharply in recent days
Official spokesman Thaer Naqib said the emergency would cover the whole of Iraq except Kurdish-run areas in the north.
He said the move came in response to mass killings and destruction of the country's infrastructure carried out by "criminals and terrorists".
He said the violence was part of a plot to derail the interim Iraq government's progress towards January's elections.
In the latest violence, Iraqi insurgents stormed a police station in the western province of al-Anbar, disarmed 21 officers and shot them dead.
Fighting at the Haditha police station, 200km (120 miles) west of Baghdad, lasted about 90 minutes, sources say, as the building was attacked with rocket-propelled grenades and mortars.
In other violence on Sunday:
- Another six policemen were shot dead in a similar attack in the neighbouring town of Haqlaniya
- Two British soldiers from the Black Watch battle group stationed at Camp Dogwood, 20 miles (32km) from Baghdad, were seriously injured in a suicide attack
- Three Iraqi officials from Diyala province were killed on their way to the funeral of a colleague
- One US soldier was killed and four others wounded in a car bomb attack in western Baghdad, the US military said
- Another car bomb went off in Baghdad outside the house of Finance Minister Adel Abdul Mahdi. The minister was not at home at the time, but one of his guards was killed
- A British contractor was killed in a roadside bomb attack in Zubayr, south Iraq, a British army spokesman said.
On Saturday, more than 30 people were killed in another rebel stronghold, Samarra, which US forces only recently declared they had regained control of.
It is not clear at this stage what the state of emergency will mean in practice.
Interim Prime Minister Iyad Allawi is due to give full details on Monday.
STATE OF EMERGENCY
Prime Minister has power* to:
Restrict freedom of movement, assembly and use of weapons
Cordon off and search suspect areas
Freeze assets of suspected insurgents
Conduct military and security operations in suspect areas with the aid of US-led multinational forces
*Under the National Safety Law passed in July
However, the BBC's Alastair Leithead in Baghdad says it could include a curfew and extra powers for the police and military.
The insurgents' offensive is seen as a response to a planned assault by US troops on their stronghold of Falluja.
American and Iraqi forces are continuing preparations for the attack, amid reports that more than 100 insurgents have volunteered to drive suicide car bombs into the advancing troops.
There has been artillery fire on positions inside the city, with American aircraft heard almost continuously overhead.
As well as the risk of suicide attacks, US commanders said they expected resistance to an offensive to include car bombs and even crude chemical weapons.
Mr Allawi still hopes to avoid a US-led attack on Falluja, but feels he cannot wait much longer, his spokesman said on Sunday.
"He still hopes that it may be possible to avoid a major
military confrontation in Falluja and is now - together with
his ministerial colleagues - engaged in a last-ditch effort to see if a peaceful solution can be found," Thaer Naqib was quoted as saying by Reuters news agency.
The BBC's Paul Wood, embedded with the US Marines, says they believe that Falluja will be their biggest engagement since Hue, the Vietnamese city they captured in 1968, losing 142 men and killing thousands of the enemy.
It is reported from inside Falluja that insurgents, tribal chiefs and Sunni Muslim clerics have invited the media to enter the city under their protection to witness any assault, which they described as a crusade against Islam.