Iraq's interior ministry has announced plans to increase security in Baghdad by digging trenches around the city, and surrounding it with checkpoints.
All remaining ways into Baghdad would be via security checkpoints
The plan was unveiled amid continuing violence in the capital. At least 49 bodies have been recovered from the city's streets in the past 24 hours.
A spokesman said the security plan was designed to prevent insurgents from getting into and out of Baghdad.
But correspondents say it could take months to dig trenches round the city.
The Iraqi capital has a circumference of around 80km (50 miles).
Brigadier Abdul Karim of the interior ministry told the BBC that hundreds of minor roads would be sealed off under the plan, so that the city could only be accessed via 28 checkpoints.
He said equipment to detect weapons and explosives would be installed at key locations.
The plan, he said, would start coming into effect in less than three weeks.
Signs of torture
Meanwhile dozens of bodies were found in the capital on Thursday and Friday, taking the total number discovered in the past three days to more than 100.
A spokesman said most of the latest victims had been shot in the head, and showed signs of having been tortured.
Sectarian violence is claiming dozens of victims in Baghdad daily
Correspondents say some of those killed were probably the victims of attacks by sectarian militias.
Others could have been targeted by criminal gangs hoping to obtain ransoms.
Also on Friday, US military officials said insurgents had killed seven US servicemen and wounded dozens more in the past 48 hours across Iraq.
So far in September, 25 US soldiers have been killed.
Separately, Iraqi security forces in Basra are expected to begin a large-scale operation against sectarian militias within the next few days.
Iraq's second city has not suffered as much violence as Baghdad, but local security officials say they are determined to end the activities of death squads and mortar attacks on residential areas.
James Shaw, a BBC correspondent in Iraq, says the vast majority of the population in Basra is Shia, which means there is less activity by Sunni insurgents than in the capital. But those Sunnis who do live in the city have been targeted by Shia death squads.
General Ali Hammadi, in charge of the city's security committee, said that thousands of Iraqi troops would be used in a series of operations over the next few months to try to uproot the militias and other criminal gangs.
They will be backed by British forces based near the city.
The task will be made more complicated by the fact that there is thought to be widespread infiltration of the security forces by militia members, our correspondent says.