The relationship between the United States and Uzbekistan soured recently after the United States called for an independent investigation of a bloody incident in the Uzbek city of Andijon. It is not entirely clear just what occurred in the city in May.

The alleged massacre of civilians in the provincial capital of Andijon scuttled a flourishing security relationship between the United States and Uzbekistan that began after the terrorist attacks in New York four years ago. Emerging from talks Tuesday with Uzbek President Islam Karimov, Assistant Secretary of State for European and Eurasian Affairs Dan Fried said the issue remains contentious.

"I would say we did not fully agree, either about the events of Andijon or the nature of American support for NGOs [Non-Governmental Organizations] and democracy," he said.

But a leading American analyst of Central Asian affairs has sharply criticized both human rights groups and the U.S. government for what he says is premature judgment about the events in Andijon. Frederick Starr, chairman of the Central-Asia Caucusus Institute at the Nitze School of Advanced International Studies at Johns Hopkins University, says the available evidence is inconclusive.

"Various groups with a strong interest in a particular view of events took over - human rights organizations, many of which had conscientious observers, I have no doubt about it, but many of whose observers were also people with a strong commitment to a particular outcome, namely, making the government of Uzbekistan look as bad as possible," he said.

Figuring out what actually happened in a confused and chaotic situation can be difficult. It is compounded in a closed society like that of Uzbekistan, where President Islam Karimov's autocratic rule is considered by some to be not far removed from the old Soviet days.

This much is undisputed. In the late night of May 12 or early on the 13, armed gunmen, believed to be members of a banned Islamist movement, attacked an army barracks, a police station, and the local prison in Andijon, freeing a large number of inmates. They then occupied a government building on the main square and a crowd assembled in the square.

Rachel Denber, deputy director for Europe and Central Asia at Human Rights Watch, says the crowd was carrying out a peaceful political demonstration when government forces fired opened fire.

"I do not know whether those insurgents planned to overthrow the government," she said. "I do not know whether the mass demonstration was part of their plan. I do know, we do know, that a lot of people came to the demonstration that day on their own free will to air their grievances. And we do know as they left the square that day, they were gunned down. And we do know that the vast, vast, overwhelming majority of the people on that square, and of the people who left that square, were unarmed. And we do know that hundreds of people ended up dying."

But Mr. Starr says armed insurgents were mixed into the crowd. The institute's own report says the demonstrators were there at the urging of the insurgents.

"Did the government of Uzbekistan behave badly in this instance," he asked. "I am certainly quite prepared to believe that. But I think there is in any tragedy of this sort plenty of blame to go around. At the very least, the excessive statements that this was Uzbekistan's Tiananmen Square are clearly not warranted. I do not believe the people in Tiananmen Square had submachine guns."

The Uzbek government denies it killed civilians, saying 187 people were killed and about 300 wounded as it was putting down an armed uprising by Islamic radicals. President Karimov rejected calls by the United States and the European Community for an independent international inquiry into the events of Andijon.

Human Rights Watch and Amnesty International base their accounts on interviews with refugees from Andijon who fled to neighboring Kyrgyzstan. The Central Asia Institute issued its own report by Shirin Akiner, a lecturer in Central Asian Studies at the University of London, who was on a trip to Uzbekistan and managed to visit Andijon shortly after the event and interview people there. Her report says the death toll was probably closer to the government's tally than the higher ones that have appeared.

Ms. Denber of Human Rights Watch says the evidence is clear about what happened.

"I think it is true that there is a fair amount of information that we lack of hard scientific information because the government won't make that available," she said. "But I do not think there is any doubt about a couple of things. And one is that many people came to the square that day to vent their grievances, and that they did so on their own free will, that the vast majority of them were unarmed, and that hundreds of people who were unarmed were gunned down, and that they were gunned down by government forces."

However, Mr. Starr says the Human Rights Watch testimony cannot be accurately evaluated since so much of it came from anonymous sources, apparently afraid to be identified. He says such anonymous denunciations are akin to the old days in Uzbekistan.

"It is anonymous evidence. This is Stalinism," he said. "Just because it is in the name of human rights does not change its character. They must address this problem. They are hurting the very cause that they represent and which we all support."

Ms. Akiner's report identifies some of the 40 sources she interviewed only in general terms, such as doctor or prison staff and none by name.

The Uzbek government has rejected any independent inquiry, but has organized its own international commission to investigate Andijon, which includes jurists from China, India, and Russia.