By Natalia Antelava BBC News, Almaty

Survivors and rights groups say hundreds were killed

Exiled Uzbek opposition groups have appealed to the international community to put more pressure on the country's president, Islam Karimov.

Their calls were designed to mark the second anniversary of the killings in the eastern Uzbek city of Andijan, on 13 May 2005.

Hundreds of civilians are believed to have died when Mr Karimov's troops opened fire on demonstrators.

Mr Karimov has repeatedly rejected demands for an inquiry.

His government said the demonstrators were armed and that the military liquidated a gang of Islamic terrorists.

While Uzbek groups abroad have staged small demonstrations to remember the victims of Andijan, inside Uzbekistan no-one is marking the anniversary of the killings - or at least, not publicly.

In a recent speech, President Karimov said the country had moved on.

But there are plenty of unanswered questions about what exactly happened in Andijan.

According to Mr Karimov, it was an attempted Islamic uprising, during which his troops killed 187 radicals.

But hundreds who fled the events tell a very different story.

Backing up their version, human rights groups say it was a massacre of civilians and that up to 1,000 people could have been killed.

And since then, hundreds of people linked to the events have been arrested on charges of religious extremism, among them are many journalists and human rights activists.

Those who managed to escape say Andijan has triggered an unprecedented government repression.

They talk about the deepening climate of fear, about secret trials and torture in prison, about mass graves dug by the soldiers after the killings.

Most of it is impossible to verify.