Scientific tests are to be carried out on bodies found in a mass grave in Afghanistan to try to determine the age of the human remains.
The site was used by the military during the Soviet occupation
Afghan officials announced that the grave had been discovered earlier this month.
A special commission has been to visit the site, in the desert near the capital, Kabul.
The commission says it will complete its investigation and report back to President Hamid Karzai.
In a flat, barren plateau outside Kabul is Chamtala, the desert area where a huge mass grave was unearthed earlier this month.
Police were led to it by an elderly man who worked as a driver for the Soviet Army when it was in Afghanistan in the 1980s.
A high-level commission headed by a former chief justice has now visited the site and seen some of the bodies it contains - reportedly several hundred in a series of underground rooms.
A forensic doctor says many of the bodies are in a seated position and there are still fragments of clothes and even of flesh.
Afghan officials said that they had found hundreds of bodies
The commission head said an atrocity had been committed and that his team would make an open investigation and report to the president within a week.
The head of the police's criminal department, Gen Ali Shah Paktiwal, said documents and clothing found at the site would help with the investigation and that scientific tests would be used to establish the age of the bodies.
The site of the grave is a former defence base used jointly by the Afghan and Soviet governments during the occupation.
General Paktiwal quotes the former driver as saying the Russians tortured and shot people there.
Some government sources, however, believe the mass grave may date from the more recent civil war of the early 1990s.
Even if the identity of the killers is discovered, it is not clear whether there will be trials, because parliament recently voted to grant a broad amnesty to war criminals.
Human rights workers say more than twenty mass graves have so far been unearthed around Afghanistan, covering all periods of the country's conflict.