Confusion reigned last night over what caused two Russian airliners to crash almost simultaneously, killing all 89 people on board and raising fears of suicide hijackings by Chechen separatists just days before the region elects a new president.
A Tu-154 jet flying from Moscow to the Black Sea resort of Sochi disappeared from radar screens at 10.59 p.m. (7.59 p.m. Irish time) on Tuesday night, three minutes after air traffic control lost contact with a Tu-134 plane heading from the same Moscow airport to the southern city of Volgograd.
Wreckage of the Volga-Aviaexpress Tu-134 was found in fields about 100 miles south of Moscow, while rescuers discovered the remains of the Tu-154, operated by Russia's second-largest airline, Sibir, about 500 miles further south, near the town of Rostov.
Sibir said the pilot of its plane had sent a hijack alert moments before it disappeared, and local people said they heard explosions in the sky just before the Volga-Aviaexpress plane plunged to earth from 33,000 feet.
Prosecutor General Mr Vladimir Ustinov told President Vladimir Putin he had no clear view of what happened to the planes, which took off from Moscow's Domodedovo airport.
"We are examining a number of versions, among them a terrorist act, and human and technical factors," Mr Ustinov told Mr Putin during a meeting with the heads of the FSB security service and the Emergencies Ministry shown on television.
FSB domestic security service, which was called in to investigate the crashes, denied finding any evidence of a terror attack.
"The main line of inquiry we are following is violation of the operating rules for civil aircraft," said FSB spokesman Mr Sergei Ignatchenko, while adding that explosives experts were still working at the crash scenes.
"We are also examining the possibility of a terrorist act, but we have no evidence to support this," he said.
President Putin, a former head of the FSB, returned from his holiday in Sochi to order a full investigation into crashes that sparked worries of an unprecedented attack by Chechen rebels who have vowed to disrupt this Sunday's election to find a new leader for the war-shattered republic, three months after the last one was assassinated. Last night he expressed his condolences to the victims' relatives at a meeting with law enforcement chiefs, and declared today a day of mourning.
Sibir appeared to reject mechanical failure as the cause of the crash of its plane, which sent out a hijack alert in its final moments.
"The message was generated right before all contact was lost with the plane and it disappeared from radar screens," Sibir said in a statement which also suggested that the aircraft, which had 46 people on board, may have been blown up.
"The wide distribution of large fragments indirectly confirms the conjecture that the plane broke up in mid-air because of an explosion," the company said.
But Mr Sergei Kovalyov, president of Russia's Federal Union of Air Traffic Controllers, said officials had told him the Tu-154 had issued a general distress call that did not specify the nature of the problem.Yet he said he believed that terrorists were responsible. "When you see two simultaneous, identical events, it is difficult to imagine anything else."
Security was stepped up at airports nationwide amid fears of a wave of violence by Chechen's separatist rebels, who are fighting their second war in a decade with Russian troops.
But a spokesman for guerrilla leader Mr Aslan Maskhadov immediately denied any responsibility for the plane crashes. "To us any form of terrorism is absolutely unacceptable. We have condemned it and continue to condemn it," Mr Akhmed Zakayev told Reuters in London.
