An Australian forensic expert speaks near a mass grave. The Iraqi High Tribunal is exhuming bodies from mass graves as it prepares trials against members of the toppled Saddam Hussein regime over the suppression of a 1991 Shiite uprising. [AFP]

He said the killings were carried out in desert areas where the victims could be thrown into shallow embankments or simply shot there.

The bodies of 28 men, estimated to be 20 to 35 years old, have been found so far in one of the graves, with small blue, yellow and red flags marking the findings - including spent cartridges and bullets. One wrist still bore a watch.

The victims were wearing clothing favored by Shiites, including dishdashas, and most were blindfolded. The blindfolds appear to have been fashioned from keffiyehs, traditional Arab headdresses, said Kerry Grant, a 45-year-old Australian forensic archaeologist at the site.

One skeleton was wearing a blue jacket and his hands were behind his back, suggesting they had been tied. A plastic flip flop, a tennis shoe and some skulls with hair on them also could be seen at the site.

"Going by the clothing, I think they were grabbed very quickly," Grant said.

The leaders of the team of about 120 people said they were motivated to keep working, despite searing heat, by their desire for justice for the victims.

"When you work with the remains for a long time, you get very attached to them and you feel very badly for them," Trimble said, adding the remains would be repatriated when they were no longer needed as evidence.

Kerry also expressed regret that the team was unlikely to find all the bodies dumped in the area of about three miles.

"We know there is more in the area, but there is only so much we can do. We can't be here too long," she said.

The second site - in a ravine about 72 feet deep and 33 feet wide - had only been under excavation since late last week.