Updated

The knowledge weighed heavily on local Iraqis -- the location of mass graves that witnesses say are filled with those who dared to defy Saddam Hussein's (search) absolute power.

Human rights groups say Iraq is dotted with such graves. But before Saddam's government fell, citizens who knew or suspected were forbidden to go to the sites.

Now free to search for missing relatives, Iraqis on Saturday and Sunday dug up 72 bodies from a shallow mass grave 13 miles northwest of Najaf, one of Shiite Muslims' holiest cities. Bullet casings also were found in and near the graves.

Witnesses said the grave was filled with the bodies of men and women executed after a failed Shiite uprising against Saddam's regime in 1991.

"Everybody knew and could see, but they kept quiet," said Kamel al-Tamimi, a farmer. "We were told to stay away from this area, not to go near it, that it was a security zone."

Iraqis exhumed bodies with shovels and their bare hands, and they expected to find more remains this week. Others were searching the region around Najaf for additional mass grave sites in the area. At least one smaller site turned up a few miles away and was guarded by U.S. Marines.

"This is the tip of the iceberg in this country," said Marine Capt. Mike Urena. "I am sure you will find more."

More than 25 bodies were unearthed Saturday, and at least 10 had been identified, local Iraqis said. Another 47 sets of remains, including those of women, were uncovered Sunday afternoon. At least some of the victims were apparently lined up and shot.

It was unclear how many bodies were buried at the site near Najaf, but several mounds dotted the flat farmland -- mounds that U.S. Marines said could mark additional gravesites.

"I'm looking for my relatives," said Jawad Shaker, searching the site. Another person was searching for a nephew who disappeared in 1991.

The large grave being excavated Sunday, residents said, was linked to the Shiite uprising that took place after the 1991 Gulf War (search). Shiites seized control of most of Iraq's south, and Saddam's forces used helicopter gunships and tanks to defeat the lightly armed rebels.

Thousands of people are believed to have been executed after the failed revolt. Shiites, a minority in the Islamic world, make up 60 percent of Iraq's Muslims and were ruled for a generation by Saddam's overwhelmingly Sunni Muslim Baath Party.

On Sunday, as five people dug away at the site, a farmer who refused to give his name said he saw blindfolded people, hands tied behind them, shot in the back of the head after the uprising.

A few miles away, Marines guarded another site where two bodies and four bullet casings were found. A red keffiyah was wrapped around the eyes of a skull. Some bodies had identification cards in their pockets.

At the larger site, unearthed items included women's blue and black slippers; a comb; a piece of a traditional cloak; decaying gray pants; fragments of wristwatches.

The remains found over the weekend were wrapped in white shrouds after they were dabbed in sand, a Muslim ritual. Plastic bags tied to the shrouds contained some of the dead people's belongings. Names that had been handwritten in ink on most of the identity cards had faded, though some cards still had photos.

The Supreme Council for the Islamic Revolution in Iraq (search), a Shiite Muslim group, was directing the excavation of the site and said it was preparing a special section of a cemetery for what it called the "Martyrs of the 1991 Uprising."

Later Sunday, the Marines handed over control of their site to the Iraqi Unity Association, led by U.S.-appointed Gov. Abdel-Monem Abboud.

Before they left, the troops barred local farmers and Supreme Council representatives from approaching the mass graves. Marine Cpl. Sean O'Meara assured onlookers that special care would be taken to ensure Muslim law is followed at the site, but many were angry nonetheless.

"Islam dictates that the remains of one person should not be mixed with those of others when they are buried. We take good care of the remains," Abu Mujahed, a farmer, insisted as he stood a few yards away from a guarded grave.

"They are not letting us see our relatives," he said. "My cousin is there. We prefer to dig them ourselves. We can identify them from their clothes."