Top Chechen envoy Ahmed Zakayev, in Denmark for a world congress of the Chechen people, was arrested here at Russia's request, the police announced.Danish television said he was suspected of involvement in last week's deadly Moscow hostage-taking by Chechen nationalists, who were demanding that Russia pull its troops out of the tiny Chechnya republic.

The arrest comes as Russian President Vladimir Putin has made good on a vow to crack down on Chechen separatists, with dozens of people arrested in Russia on Tuesday in the wake of the Moscow theatre siege.

At least 117 hostages and around 50 Chechen hostage-takers were killed, most of them gassed to death by Russian forces in an assault on the theatre where more than 800 people were taken by the nationalists on Wednesday.

Zakayev was in Denmark as an envoy of Caucus Chechen president Aslan Maskhadov, who on Monday again said he was prepared for negotiations with Moscow to put an end to the bloodshed in the tiny breakaway republic.

Danish television network TV2 reported that Zakayev was also sought in connection with a number of "terrorist" incidents since 1996, and that police here had received the request for his arrest on Friday.

It said that Danish police officials requested extra information to justify his arrest, and that the information had been judged sufficient to warrant his being taken into custody.

Zakayev was due in a Copenhagen court later Wednesday for a hearing to determine if he will be formally detained, it said, adding that Russia had asked for his extradition.

Chechnya has been a killing field since 1994 when a first war erupted between nationalists, who want to break free from Russian control, and Russian troops sent in to quash the insurgency.

That war in ended in 1996, after which Chechnya had de facto independence from Russian control. But Russian forces went storming back in to the region in October 1999.

nationalists fighters on Tuesday downed a Russian helicopter near the Chechen capital Grozny, leaving four dead, Russia's Interfax news agency reported.

With Russia still in mourning, and facing international criticism over the gassing of the victims and the handling of the crisis, Defence Minister Sergei Ivanov said Tuesday that Russia would crack down on the nationalists.

"We understand that the terrorist threat to Russia, including from outside, is increasing," Ivanov said in televised remarks.

"I do not mean only perpetrators of terrorist attacks, but accomplices and those who provide financial support as well," he said after a meeting with Putin.

PHOTO CAPTION
Akhmed Zakayev, senior representative for Chechnya 's nationalist President Aslan Maskhadov, speaks at a news conference in Copenhagen in this Oct. 24, 2002, file photo. Danish police arrested Zakayev after receiving information from Russian authorities that said Zakayev was suspected of helping prepare the siege of a Moscow theater last week and other acts between 1996 and 1999. (Scanpix/Reuters)