The graves, dug into a large, terraced hill, were decorated with headstones, mounds of white pebbles, flags and brightly colored ribbons, said Capt. Philip Nicholson, one of about 400 Canadian soldiers who returned to base Tuesday after a four-day mission in eastern Afghanistan.
He said there was no indication that the al Qaeda leader was in one of the graves. Forensics experts from the U.S. Army's criminal investigation department collected DNA samples from the corpses unearthed at Ali Khayle, about 60 miles southeast of the capital, Kabul, said U.S. military spokesman Maj. Bryan Hilferty.
Canadian battalion commander Lt. Col. Pat Stogran said DNA samples had been taken from two other bodies found on a nearby mountain ridge. He said the samples would be handed over to American experts.
Bin Laden was thought to have been at Tora Bora in December during an intense U.S. bombing campaign that was backed by Afghan ground troops and U.S. special forces. It's not known if bin Laden died there or escaped.
"Certainly there was the possibility that bin Laden was among them, that's why we proceeded with the excavation," said Nicholson.
One prominent grave was initially thought to possibly be that of bin Laden, but visual inspection of the body showed it was not the al Qaeda leader.
"It was hard to identify anybody," Nicholson said, adding the bodies were badly decayed and that many had shrapnel wounds. "Osama bin Laden is approximately 6-foot-5 and we did not find anybody that was 6-foot-5. That being said, we did take DNA samples and they are going back to the United States to be analyzed."
Canadian troops discovered the graves when they went to Ali Khayle to search caves and bunkers and villagers told them about the bodies, Stogran said. The villagers said the graves contained the bodies of important al Qaeda members.
"We believe these were bin Laden's lieutenants, his personal bodyguards," Nicholson said.
Stogran said dozens of other al Qaeda fighters had been killed in the valley during last year's bombing but "the ones that we actually exhumed were treated in a special manner by the local people and that led us to believe that these were perhaps more important members of the al Qaeda."
Stogran said the graves were surrounded by electric lights to illuminate them at night.
"The locals told us ... one of them was a very big man and he had received special treatment during his burial," Stogran said.
Villagers said the body was booby-trapped with hand-grenades, but that was not the case, Stogran said.
After the U.S. bombings ended in mid-December, local Taliban officials ordered villagers to give the bodies a proper Islamic burial, Nicholson said. Villagers said the corpses were all Arabs and were buried in a ceremony Dec. 30 attended by 750 to 1,000 people.
Nicholson said that one day after the three most ornate graves were exhumed and the bodies reburied, troops returned in the morning to find that someone had planted incense sticks in them and set them alight. He said all the corpses were reburied as they were initially found.
Nicholson said small numbers of villagers and pilgrims from Pakistan still go to the border town to visit the grave site. He said they considered it a "shrine to martyrdom."
Operation Torii began Saturday and was backed by Afghan infantry units, U.S. special forces and U.S. attack helicopters. The Canadians returned to Bagram air base in twin-rotor Chinooks, lugging crates of unspent ammunition and water.
No casualties were reported and no al Qaeda or Taliban fighters were spotted, a Canadian military spokesman, Lt. Luc Charron, said.
A similar 1,000-man British-led operation that began last week is also under way in the southeast.
Both missions fall under the umbrella of Operation Mountain Lion — the overall U.S.-led search for Taliban and al Qaeda fighters in the eastern half of Afghanistan.
The United Nations said a U.N. team of forensic scientists examining three alleged mass graves in northern Afghanistan found evidence of summary executions and death by suffocation.
The site is the same one made public last week by the U.S.-based Physicians for Human Rights which said the grave was believed to hold the bodies of hundreds of Taliban prisoners who died while captives of their northern alliance foes last fall. The interim Afghan regime is now made up of many members of the alliance.
The U.N. team also examined two smaller, apparently older sites and found evidence of summary executions, said U.N. spokesman Manoel de Almeida e Silva. All of those victims, he said, appeared to be men of Hazara ethnic origin, whom Afghanistan's former Taliban rulers were accused of slaughtering in the late 1990s.
The U.N. team was preparing a list of other possible mass-grave sites, Almeida said.
In other developments: