By Sarah Rainsford BBC correspondent in Moscow

Putin and politicians paid their respects

Some 129 hostages died in the siege, almost all of them killed by incapacitating gas that was pumped into the building to end the stand-off.

The modest ceremony in Moscow began with a minute of silence, a moment to remember the dead.

A few women shed quiet tears as they stood before the theatre where the hostage crisis was played out last October.

New memorial

Some clutched framed photographs of their relatives, others carried slim red candles and bundles of flowers.

Reaching into the freezing winter sky above them was a new memorial to the victims of the siege: a plain column, topped with a sculpture of birds.

Many relatives want justice

It marks the day that rebels from Chechnya brought their fight against Russia to the capital.

"There can be no forgiveness for the hostage takers," one official told the crowd. "There can only be contempt."

Mayor Yury Luzhkov talked of a tragedy. And there was a peculiar moment of pathos, as the singer who last year helped liaise with the rebels mimed out of time to a piped recording of his song.

Anger

Then one by one, family and friends of the dead filed to the foot of the memorial to lay their tributes. The politicians brought wreaths anxious too to make a show of support.

They remember us for this anniversary, but otherwise I'm alone with my pain Relative

But mixed with the grief in the crowd was anger. Many relatives said they wanted justice from officials, not what they called empty words or meaningless monuments.

Most of all they are still looking for someone to stand-up and shoulder the responsibility for what happened.

'Too weak'

And one woman whose 30-year old daughter Irina died in the siege said she felt she had been forgotten.

"They remember us for this anniversary, but otherwise I'm alone with my pain," she said.

People want to know why doctors were kept in the dark

"The money we got from the state was only enough to pay for the funeral. It's all gone now."

Lydia's daughter Dasha was 13. She was enjoying a night at the theatre with a group of school friends when the rebel gunmen broke onto the stage.

To this day her mother can barely contain her anger at the way the siege was brought to an end, at how Russian special forces pumped a powerful stun-gas into the building, then smashed their way through the doors.

Lydia says her daughter had a cold. She was too weak to survive the gas.

"The state has destroyed its own people! Its children!" Lydia told me. "Just look how many children died."

Lack of information

Dozens of relatives like Lydia are still waiting for answers. They want someone to tell them why the gas was used at all.

They want to know why so few doctors were on hand and why those that were, were not told what substance they were dealing with. Many suspect they are the victims of an official cover-up.

If they had to use gas, they should have made sure 800 doctors were sent to treat the 800 hostages Dmitry Milovidov

Dmitry Milovidov believes his daughter Nina stood no chance. "The dose was measured for the rebels, not children - but it reached them too," Dmitry said, surrounded by photos of his eldest child.

"The government should have negotiated with the rebels. Or if they had to use gas, they should have made sure 800 doctors were sent to treat the 800 hostages."

Accused of greed

Many families have tried to pursue claims for damages in the hope a positive verdict would point to who is to blame.

Instead they have been accused of greed, for seeking unprecedented amounts in compensation.

One by one their cases were thrown out of court. Officially the rescue operation is hailed as a success. President Putin himself continues to insist that the gas used was harmless.

And there is a chilling new statistic to mark this anniversary.

The theatre siege was followed by a wave of suicide bombings in Russia that the authorities blame on Chechen rebels.