HIGHLIGHTS: Chechen Congress Meets in Copenhagen Monday to Discuss Peaceful Solution to Russian-Chechen Conflict||Questions Mount as Russia Mourns Theatre Dead||Deposed Elected Chechen Leadership Says Theatre Attackers Beyond its Control, Warns Others Could Strike again with Catastrophic Consequences for Chechnya, Russia & Europe||STORY: A European Union-Russian summit will be moved to Brussels after Russian President Vladimir Putin threatened not to travel to Denmark if a meeting of Chechen nationalists was permitted, the Danish foreign minister said Sunday.

Russia had threatened to cancel the EU and the bilateral meetings if a two-day World Chechen Congress was allowed to begin on Monday despite a hostage-taking crisis in which Chechen fighters held hundreds of hostages for more than two days in a Moscow theater.

The Danish government replied that the meeting could not be banned because of the constitutional right of freedom of speech and assembly in the Scandinavian nation of 5.3 million.

Putin and EU leaders are expected to discuss a plan to allow citizens from the Baltic Sea enclave of Kaliningrad travel through EU territory to the rest of Russia after Lithuania and Poland - which surround Kaliningrad's borders - join the EU in 2004.

The Chechen Congress was expected to gather Chechen representatives of the nationalist government of deposed elected Chechen President Aslan Maskhadov, Russian human rights organizations and lawmakers from Russia and other European countries for discussions on a peaceful solution to the Russian-Chechen conflict.

Russian forces retreated from Chechnya in 1996 and returned three years later after Chechen attacks on a neighboring Russian region and after apartment house bombings blamed on the Chechens killed more than 300 in Russian cities.

QUESTIONS MOUNT AS RUSSIA MOURNS THEATRE DEAD

President Vladimir Putin leads Russians in a day of mourning on Monday with his people asking how more than 100 hostages were killed by mystery gas used to knock out Chechen hostage-takers.

As of Sunday evening, Moscow's top doctor Andrei Seltsovsky said 646 people were still in hospital, including 150 in intensive care, 45 of them in a grave condition.

Early reports on Saturday said only around 10 hostages had died, suggesting that the operation had been more successful than had first seemed possible.

But the death toll rose inexorably. During Saturday it hit 67, then over 90, before reaching 117 on Sunday. Only two died from gunshots.

For President Vladimir Putin, the rising death toll was an uncomfortable reminder of two other tragedies which have blighted his term of office.

In August 2000, the nuclear submarine Kursk sunk after a torpedo exploded on board, killing 118. Putin was widely criticized for a perceived failure to act decisively then.

Earlier this year a helicopter was shot down over Chechnya with a similar number of deaths, despite Putin's repeated claims that the Chechen war, launched in September 1999 -- months ahead of the election which made him president -- was all but over.

CHECHEN FIGHTERS COULD STRIKE AGAIN

In Copenhagen, the envoy of Chechen leader Aslan Maskhadov said Sunday Chechen fighters, like the group that took Moscow theater-goers hostage, may take even more drastic action to oust Russian forces from their Muslim homeland.

Akhmed Zakayev said Chechnya's elected leaders were ready for a political solution with Moscow but that desperate Chechen fighters were beyond their control.

"Terrorist acts are possible. We cannot exclude that the next such group takes over some nuclear facility. The results may be catastrophic, not only for Russian society and for Chechen society but for the whole of Europe," he said.

PHOTO CAPTION

The Russian presidential standard flies at half staff over the Kremlin as Russia observes a day of mourning October 28, 2002. Russia lowered national flags and cancelled entertainment across the country on Monday to mourn the victims of the hostage taking drama in Moscow. REUTERS/Alexander Natrusk