A Muslim rebel group claimed Wednesday it had seized control of a small Uzbek town on the border of Kyrgyzstan and vowed to build an Islamic state. Diplomats briefly toured a nearby city where government troops fired on demonstrators, reportedly killing hundreds.

The United Nations' human rights chief called Wednesday for an independent investigation into recent killings in Uzbekistan and expressed concern over reports of excessive use of force by authorities.

Rebel leader Bakhtiyor Rakhimov (search) said his forces controlled Korasuv (search), a town of 20,000, and were ready to fight any government troops that came to crush his rebellion. An AP reporter in Korasuv saw no sign of government officials in the town.

"The town is in the hands of people. People are tired of slavery," Rakhimov told The Associated Press while leaning down from the back of a horse. "We will be building an Islamic state here in accordance with the Quran."

The group claimed to have 5,000 militants.

The government of President Islam Karimov (search) dismissed Rakhimov's claims.

"It's all sheer nonsense, everything is normal there," Uzbek Interior Minister Zakir Almatov said when asked whether the government would move against the insurgents in Korasuv.

The uprising in Korasuv began with attacks on police and government posts Saturday, a day after the region exploded in unrest when thousands of protesters took to the streets of Andijan, Uzbekistan's fourth-largest city.

The unrest was sparked by economic hardship and rage over the trial of 23 Muslims accused of being members of a group allied with the outlawed radical Islamic party Hizb-ut-Tahrir (search). The group seeks to create a worldwide Islamic state and has been forced underground throughout most of Central Asia and Russia.

Karimov's hardline secular regime has a long history of repressing Muslims who worship outside state-approved mosques. Karimov blamed the unrest in Andijan on extremist Islamic groups that seek to overthrow his government and create an Islamic state.

Troops loyal to the government put down a protest Friday in Andijan and reportedly shot and killed civilians in another town, Pakhtabad (search), over the weekend.

But the interior minister dismissed as "nonsense" allegations of a crackdown by troops in Pakhtabad.

"Clashes only occurred in Andijan," Almatov said.

The government has denied its troops fired on any civilians, though an AP reporter saw troops shooting at protesters in Andijan (search) on Friday.

Accounts of the death toll have varied greatly so far. The government said 169 died in Andijan. Opposition activists say more than 700 were killed — more than 500 in Andijan and about 200 in Pakhtabad — mostly civilians.

United Nations High Commissioner for Human Rights Louise Arbour (search) said Wednesday that she was deeply concerned over reports about "indiscriminate and excessive use of force by law enforcement officials, followed by the imposition of restrictions on local and foreign media."

Arbour urged the Uzbek government to adhere strictly to international principles of the use of force and weapons by officials and to "guarantee the rights Uzbekistan has pledged to uphold under international law, including the freedoms of assembly and expression."

She pushed for an independent investigation into the Andijan violence.

Uzbek officials took foreign 35 diplomats and 30 journalists on a three-hour tour of Andijan on Wednesday, showing them a prison, the local administration building seized by militants during Friday's violence, several local officials and parents of a policeman who died in last week's unrest.

The people of Andijan were kept blocks away, leaving little chance for an objective assessment of the events Friday.

"We blocked a few roads for your security," Almatov told the delegation as it was bused along the streets, lined with cordons of troops and police.

The delegation was allowed to spend only about 10 minutes in one section of the square, which was at the epicenter of Friday's violence.

Almatov ignored a reporter's request to visit to a school where a prominent local doctor had said 500 bodies were stored following the violence. The doctor spoke on condition of anonymity out of fears for her safety.

The only local residents whom visitors were allowed to see were the parents of a police officer killed in the riots and several local officials, who relayed the government version of events.

Some diplomats complained the trip was too short and there was not even a chance to speak to residents.

British Ambassador David Moran (search), whose country had strongly urged Karimov's government to open Andijan for international inspection, said a more thorough survey was necessary.

"I think we need to be realistic about how much can be achieved in a whistle-stop tour of ambassadors in a large delegation format over such a short period," he said. "I think what we need now is a systematic process of openness that will enable the international community to make an authoritative assessment of the scale and the nature of what happened here."

In another section of Andijan, which the foreign delegation did not visit, dozens of heavily armed troops moved into a neighborhood in what looked like a special operation that included snipers watching from rooftops. No shooting was heard.

Nigara Khidoyatova, head of the opposition Free Peasants Party (search), said her party had estimated 745 were killed in Andijan and Pakhtabad based on conversations with relatives of the missing and funerals.

Khidoyatova's casualty estimate could not be independently verified. Karimov dismissed the claim, saying Khidoyatova "needs psychiatric treatment."