ANDIZHAN, Uzbekistan - Uzbek authorities are likely to arrest and eliminate protesters whose rebellion ended in a massacre, ushering in a new wave of repression in the ex-Soviet state, a human rights campaigner said on Monday.

The rebellion in Andizhan on Friday, sparked by the trial of 23 Muslim businessmen and blamed by President Islam Karimov on Islamic extremists, was put down by security forces in the bloodiest chapter in the country's post-Soviet history.

According to witnesses interviewed by Reuters in Andizhan, soldiers outside a school gunned down a large crowd, including women, children and 10 police hostages, that was moving away from a main square where the shooting started.

"It was a massacre," said a 31-year-old cobbler who witnessed the killing outside School No. 15 from a side street. "This sickening smell of blood, smashed brains, guts, and blood, blood, everywhere. I could not put my feet on a dry spot.

"I saw soldiers killing several wounded with single shots to the head after asking 'are there any wounded around'," he said, asking not to be named as he had been detained twice by the security services.

He said he saw about 500 corpses in comments that could not be verified but were corroborated by others.

Saidzhakhon Zainabitdinov of Uzbek rights group Appeal said a wave of repression was likely to follow.

"One can now only expect massive arrests and the elimination of those opposing the regime," he told Reuters in Andizhan.

Uzbekistan, a mostly Muslim state bordering Afghanistan, is a U.S. ally, providing use of an airbase, but has been repeatedly criticized by human rights groups for jailing dissident Muslims and the widespread use of torture.

"Pressure Valves"

	Uzbek President Islam Karimov (AFP/Getty Images)

In the strongest U.S. criticism since the crisis erupted, Secretary of State Condoleezza Rice called on Karimov to relax his tight grip on political life.

"We have been encouraging the Karimov government to make reforms, to make the system more open," she told reporters. "This is a country that needs, in a sense, (the) pressure valves that come from a more open political system."

The town remained tense on Monday, parts of the center were blocked by armored personnel carriers and troops who raised their Kalashnikov assault rifles and clicked off the safety catches at approaching pedestrians.

Single gunshots could be heard overnight.

British Foreign Minister Jack Straw, who has pressed for greater transparency from Uzbek officials who told reporters to leave Andizhan on Saturday, said the Uzbek government had pledged to let foreign diplomats visit Andizhan.

On Saturday, thousands fled the bloodshed to the closed border with Kyrgyzstan and in one border town, Kara-Suu, residents set fire to a police station and other official buildings, fanning fears the unrest might spread.

The violence in Andizhan followed protests in the nearby Kyrgyz cities of Osh and Jalal Abad, which led to the overthrow of Kyrgyz President Askar Akayev in March- the third longest-serving leader of an ex-Soviet state to go in 18 months.

Zainabitdinov said that although the uprising in Andizhan had been put down, it marked a point of no return for Karimov.

"In the final analysis it looks like the president has doomed himself and he is going to be put on trial sooner or later," said Zainabitdinov, 50.

In Tashkent, a small group of activists staged a rally to commemorate the dead. Opposition sources said activists would make their owns lists of people killed in the fighting.

In graphic testimony, witnesses told Reuters on Sunday that troops outside School No. 15 used an armoured personnel carrier's machinegun to fire at the crowd, a mix of armed rebels, protesters and onlookers including women and children.

The first to be killed were 10 police who were being held hostage and begged the soldiers not to fire, said the witnesses, a local businessman and a driver who asked not to be identified.

The third witness, the cobbler, said on Monday he had been shot at as, with others, he moved 20 wounded away.

"One boy aged 15 had one half of his right leg torn off by a large-caliber bullet. One half of his right arm was swinging on a bit of skin," he said. "He died 15 minutes after I brought him to the schoolyard."

Officials have said 10 police and "many more" rebels were killed, but have denied opening fire on civilians. Prosecutors in Tashkent said a formal investigation had been launched into "murders and the organization of mass unrest" in Andizhan.

This correspondent saw bullet marks that riddled the facade of School No. 15. The pavement, street and gutters outside were covered with blood and body parts, hastily sprinkled with soil.

Additional reporting by Maria Golovnina in Tashkent and Shamil Baigin in Kara-Suu