An Uzbek rights activist said Tuesday that she saw about 500 bodies in the eastern Uzbek city of Andijan (search) after troops fired on protesters, contradicting the official claim that 169 died.

Gulbakhor Turayeva (search), a former doctor turned rights activist, said she counted 400 bodies lying in the yard of Andijan's School No. 15 a day after the violence. She said there were about 100 other bodies there, but that she had been driven out of the school before she could make a precise count.

Government troops shot at demonstrators in Andijan on May 13 after protesters stormed a local prison and government headquarters. Uzbek President Islam Karimov (search) blamed the violence on Islamic militants and denied that troops had fired on unarmed civilians.

Karimov has shrugged off activists' claims that hundreds had died and stonewalled Western demands for an international inquiry, saying that Uzbek authorities would conduct their own probe. The Uzbek parliament, comprised entirely of Karimov loyalists, has set up a panel to investigate the Andijan unrest, according to a resolution published in government newspapers Tuesday.

Turayeva, who heads the Anima-Cor (search) rights group, said most of the dead she saw at the school yard were men.

"I saw bodies on the ground behind the fence, and I counted about 400 of them," Turayeva said at a news conference in the capital Tashkent. "There were more just round the corner. I would estimate their number at around 100, but the guards drove me away before I could count them."

She said she had gone to the school to check local residents' claims that it was "packed with bodies."

The toll from the violence has been difficulty to nail down. An Associated Press reporter over several days visited 16 cemeteries, but found just 61 graves that cemetery workers said belonged to victims of the violence.

Death certificates obtained by AP were marked with numbers reaching as high as 328 issued May 14, 304 on May 15 and 279 on May 16. It wasn't known if the numbers reflected a count that began each day, which would support opposition claims that hundreds died, or a count that began at the beginning of the year. Some Uzbek regional offices that record births and deaths total from the beginning of each year.

Uzbekistan's top prosecutor has said 169 people were killed, including 32 government soldiers. He said nearly all the remaining dead were Islamic militants who seized weapons and freed prisoners from a jail before security forces moved in to put down the uprising. The few civilians who died were killed by militants, Uzbek officials say.

Groups opposed to Karimov's rule say the death toll was far higher.

Nigara Khidoyatova, head of the Free Peasants party, said workers from her group recorded 745 killed. However, despite repeated requests from journalists, Khidoyatova provided a list of only 43 names without addresses or any contact details, making it impossible to confirm the alleged deaths.

Joining other Western calls for an international inquiry into the unrest, NATO said Tuesday it was "deeply disturbed" by the Andijan violence. Uzbekistan cooperates with the alliance through an Individual Partnership Action Plan (search).

"We condemn the reported use of excessive and disproportionate use by the Uzbek security forces," NATO said in a statement. "We support the United Nations' call for an independent inquiry into these events and urge the Uzbek authorities to allow such an investigation."

Human Rights Watch (search) said Tuesday that as part of an ongoing crackdown on rights defenders, the Uzbek government had arrested a prominent activist, Saidjahon Zaynabitdinov, who had strongly criticized the violence in Andijan and said the death toll could be as high as 1,000. He was detained Saturday and is being held on unknown charges, the U.S.-based rights group said.