Relatives of missing people have been excavating bodies at the site
Another mass grave has been discovered in Iraq at Salman Pak, just south of Baghdad, in the grounds of what used to be a sprawling military complex.
Relatives of missing people have begun excavating the site and on Saturday morning they recovered at least five bodies.
Local residents say they helped bury more than 100 bodies at the military complex in April and they believe many more may be hidden underground.
They say the victims were young men killed in early April, after the American-led invasion had begun.
One body was dressed in pyjamas, another had been blindfolded, while a third had his hands tied and had been shot in the back of the head.
Many of those looking for relatives told Reuters news agency they had not heard of the grave until a Shia party, Daawa, which lost many of its members to Saddam Hussein's death squads, organised a trip to the site.
Most Iraqis at the site are from Baghdad's Sadr City, a Shia slum formerly known as Saddam City.
MASS GRAVES IN IRAQ
Kirkuk: Kurdish officials report discovery of 2,000 bodies
Muhammad Sakran: Reports say more than 1,000 bodies found
Babylon: Children's bones reportedly among remains found
Al-Mahawil: Up to 15,000 bodies feared buried
Najaf: 72 bodies found
Basra: Grave believed to contain about 150 Shia Muslims
Abul Khasib: 40 bodies reportedly found
Many arrived with white sacks filled with cloth to carry away the remains of the dead.
One of them, Kathim al-Darajee, says he spent 10 years at the notorious Abu Ghraib prison and left with only one eye because the other was removed during torture.
"I am looking for my nephew. They showed him and others on television after they were tortured and said they were guilty of opposition to Saddam," he said.
Beyond these freshly-dug graves lie rows and rows of furrowed earth, where earlier victims of the regime may be buried, says the BBC's Chris Morris.
There is a huge forensic task to do here, but hardly anyone available to help, our correspondent says.
British forensic experts are investigating grave sites, but the identity of those buried will not be easy to establish because those searching for loved ones are unknowingly tampering with the evidence.
"Iraq is the land of mass graves and secret prisons," said one man.
Suspected mass grave sites have been identified right across the country.
Human rights groups believe that more than a quarter of a million people disappeared during the long rule of Saddam Hussein and the Baath Party.