Iraq has braced itself for a violent backlash from Saddam Hussein's diehard supporters if, as expected, the ousted leader is sentenced to death on Sunday for crimes against humanity.
Late on Saturday, on the eve of the verdict, police commandos killed more than 50 al Qaeda militants in a firefight on the southern outskirts of the capital, in a sign of the ferocity of the conflict, Iraqi and US officials said.
National Security Advisor Muwaffaq al-Rubaie said a total curfew would be enforced on verdict day in Baghdad and in the flash-point provinces of Diyala and Salaheddin -- including in the deposed dictator's hometown of Tikrit.
"We hope the sentence matches what this man deserves for what he has done against the Iraqi people. The Iraqi people will express happiness in the way they find appropriate," Prime Minister Nuri al-Maliki said.
"We call upon the Iraqi people to be calm, to be disciplined and to express themselves in ways that take into consideration the security challenge and the need to protect the lives of the citizens," he added.
Maliki's aide Bassam Ridha said: "We have to ensure the safety of Iraqi people from loyalists of Saddam, as Sunday is a historic day.
"We have ordered an indefinite curfew starting 6:00 am (0300 GMT) tomorrow. It will be a total curfew... for pedestrians as well as vehicles," he added.
Officials said Baghdad international airport would be barred to all civilian flights and that all military leave was cancelled in expectation of an angry response to the verdict from Saddam supporters.
"The prime minister hopes the dictator gets what he deserves," Maliki's political adviser Hussein al-Senaid said, while insisting on the independence of a tribunal much criticised for its closeness to government.
"Of course as part of the Iraqi government, we hope that he gets the maximum penalty for the crimes committed by him on the people of Iraq. We are looking forward to this historic moment. Iraq deserves justice," Ridha said.
Saddam and seven former regime officials have been accused of ordering the village of Dujail destroyed and 148 of its inhabitants executed in revenge for a failed attempt on the Iraqi leader's life in 1982.
Now, more than three and a half years since Saddam was overthrown by a US-led invasion force, Iraq's two main confessional groups are once more at war and scores of Iraqis are being killed every day in vicious sectarian attacks.
"All military personnel are on alert. Leave has been cancelled and we are on alert for any possible emergency. Those on leave should report to their units," said defence ministry spokesman Major General Ibrahim Shaker.
An interior ministry spokesman said police commandos killed 53 suspected al Qaeda militants in a fierce gunbattle on the southern outskirts of Baghdad.
"This afternoon we received intelligence reports that gunmen were endangering the security of the region," said Brigadier General Abdel Karim Khalaf, referring to the Baghdad suburb of Tuwaitha.
"They are al Qaeda. The National Police had a severe fight with them and as a result of these clashes, they killed 53 terrorists, arrested 16, burned 40 cars and seized many weapons," he said.
A US military spokeswoman confirmed the report, adding that four members of the Iraqi security services were also killed and nine wounded.
Meanwhile, a car bomb exploded in the Sadr City, a security official said, as violence in and around the Iraqi capital killed at least eight people in a other gun and bomb attacks on Saturday.
Five members of Iraqi President Jalal Talabani's security detail were killed in a roadside bomb attack on Friday in northern Iraq, a source from his party said. Talabani was out of the country at the time.
The four "received light wounds as the result of a mortar shell explosion", the foreign ministry in Moscow said. Police said one Iraqi worker was killed.