Chechen terrorists holding some 600 or more people hostage in a Moscow theatre last night warned they would start killing the captives at dawn today unless the Kremlin started pulling its 85,000 troops out of Chechnya.
The 6 a.m. Moscow time deadline added to the grim tension at the theatre in south-east Moscow.
In the first signal of Kremlin concessions to the hostage-takers, Mr Nikolai Patrushev, chief of the FSB security service and a close aide of President Vladimir Putin, made a public pledge that the lives of the Chechens would be guaranteed if they released the hostages.
Whether that would be enough to sway the estimated 40 heavily armed Chechen men and women looked doubtful since their leader, Movzar Barayev, has a reputation for brutality and ruthlessness.
The Chechens released 15 hostages, including eight children, unconditionally yesterday. And last night, four more hostages - three women and a man, all citizens of Azerbaijan - were released. But a long morning of fraught attempts to secure the release of more than 70 foreigners ended in failure and late last night the Chechens told Reuters news agency that no further hostages would be released until their demands were met.
A senior Russian security official said negotiations were being conducted with much more senior and well-known warlords in Chechnya and an unnamed foreign power was helping to mediate to try to defuse the crisis.
"Barayev is just a pawn," he said, in reference to Movsar Barayev, the leader of the terrorists.
"You need to look to Basayev and Udugov to see where he is getting his orders," he said, referring to two of the most formidable Islamist warlords in Chechnya.
The FSB security service confirmed the killings threat, which first came via hostages speaking on mobile phones to relatives and local media. An FSB spokesman said the threat was being assessed and "appropriate action" would be taken to prevent the killings. The Chechens have the theatre primed to explode if Russian forces storm the building.
Amid mounting public disquiet over Mr Putin's handling of the emergency, the Russian president declared that now was not a good time for a debate on the rights and wrongs of the Chechnya war.
He called for an agreed approach "to the single main task right now, the saving of people's lives". But he offered to talk to the terrorists. "We are open to any kind of contacts," a sombre Mr Putin said, in a television address.
He insisted, however, that past conditions stood, notably that separatists must lay down their weapons. Moscow also rejects any idea of independence for Chechnya.
The authorities banned demonstrations of protest against the war in Chechnya, though two, in Red Square and near the theatre itself, were staged yesterday.
Messages relayed by hostages via mobile phones yesterday said that the gunmen and women would starting killing hostages this morning unless the Russians started pulling out of Chechnya, the only known demand the hostage-takers have made. Mr Patrushev said negotiations were continuing. "We are holding and will keep holding talks . . . If all hostages are released, the terrorists will be guaranteed their lives," he said, after a meeting with Mr Putin.
Amid mounting desperation, the hostages sent a message: "The hostages inform all your acquaintances and all levels of the FSB, the interior ministry and the Moscow government about the inadmissibility of force. Make concession in the negotiations and on no account try to storm the building."
Speaking to a radio station from inside the theatre, hostage Ms Anna Andrianova said: "It feels like something bad is hanging in the air. People are starting to feel very bad."