[Timber Loftis]

Moscow Mourns; Envoy Criticizes Gas Secrecy
By REUTERS

Filed at 11:48 a.m. ET

MOSCOW (Reuters) - A grieving Russia buried the first victims of the Moscow theater siege Tuesday, but the U.S. ambassador said some might still be alive if the Kremlin had been less secretive about a gas that poisoned them.

After several days of U.S. praise for Putin's decisive handling of the siege, U.S. ambassador Alexander Vershbow criticized the secrecy surrounding the gas which killed 115 hostages when it was pumped into the theater to stun their Chechen captors.

And in a swift reminder to the Kremlin that the war in the rebel region of Chechnya was far from over, separatist guerrillas there shot down a military helicopter, killing four servicemen, as it landed at Moscow's main army base near the Chechen capital.

The continued presence of Russian troops in Chechnya was the main grievance of the more than 50 heavily armed Chechen guerrillas who seized the Moscow theater Wednesday to demand the soldiers' withdrawal.

All but two of the 117 hostages who died were killed by the mystery gas, believed to contain opiates, used by special Russian troops Saturday to end the three-day siege.

``To the best of our knowledge...we do think it was an opiate,'' Vershbow told a news briefing.

``We regret that the lack of information contributed to the confusion after the immediate operation to free the hostages was over. It's clear that with perhaps a little more information at least a few more of the hostages may have survived.''

The downing of the helicopter came as Defense Minister Sergei Ivanov said Russia needed to tighten security to thwart further attacks.

``We admit that the threat of terrorism against Russia, including the threat from abroad, is strengthening and we cannot but react to this fact,'' he said on state Rossiya television.

``We should take into account not only the danger which comes from the so-called humans who carry out terrorist acts, but also the danger from their allies, inspirers and financiers outside Russia.''

Under slate gray skies and drizzle, 25-year-old engineer Alexei Bochkov was buried in Moscow's vast Kuzmenskoye cemetery as 200 mourners holding carnations stood in eerie silence.

His mother, Yelena, in her late 50s, kissed his forehead for the last time, and cried: ``My Alyosha. We'll remember you for ever, for ever, for ever. God forgive us all.''

``He died from that gas, but who knows really what it was,'' said Anatoly Lazin, head of the company Bochkov worked for.

The Russian government has refused to tell even doctors treating hundreds of hostages what gas was used. Some Western experts have suggested the nerve agent BZ may have been used, not opiates.

Opiates work specifically on pain receptors, but an additional effect is sleepiness, and high doses can cause respiratory failure, a Western doctor in Moscow told Reuters.

Russian security forces said they used the gas to knock out the Chechen separatists. Many were subsequently believed shot by the troops rushing into the building, which the rebels had threatened to blow up.

A U.S. citizen died in Saturday's dawn raid in which more than 750 hostages were freed. Officials at the U.S. embassy in Moscow declined to name him.

But despite controversy over the mounting death toll and the lack of information on the gas, President Vladimir Putin was widely praised in Russian media Tuesday for his decisive action, and his popularity appears to have received a boost.

``After the tragedy at the theater, Russian society can now say with certainty that the authorities have shown they truly have authority,'' respected daily Izvestiya said.

More than 300 hostages are still being treated in hospital for the effects of the gas, 16 of them in a serious condition.

Despite backing Putin's decision to order the rescue operation, Washington has continued to press for details of the gas. U.S. officials have been told of the effects of the gas but not the name of the active agent, the embassy in Moscow said.

Doctors said three days of captivity, with little food or water, had made the hostages particularly vulnerable to the toxic agent, especially the young and old. Many died of heart or respiratory failure.

PROBE CALL

The liberal Union of Rightist Forces (SPS) demanded a parliamentary inquiry into the decision to storm the theater and security lapses that allowed more than 50 guerrillas, heavily armed and laden with explosives, to launch the audacious attack.

Mainstream separatist Chechen leaders, who accuse Russian forces of brutality away from the world's gaze, condemned the hostage-taking and again called for direct talks with the Russian government on the future of the separatist province.

They said Russia's many nuclear facilities could be the target of future attacks unless the Kremlin began meaningful peace talks rather than seek to impose a pro-Moscow government

Chechens, who have chafed at Russian rule for two centuries, complain they are an oppressed minority inside Russia. Moscow, which first sent in troops in 1994, sees an independent Chechnya as destabilizing the sensitive Caucasus region and setting an unwelcome precedent for other disaffected ethnic groups.