Amid suspicions of a double hijacking just days before an election in Chechnya, Russia has begun investigating the circumstances of two passenger jets that crashed within minutes of each other late Tuesday night.
Officials Wednesday sought to play down the possibility of a coordinated terrorist attack, saying that a safety or fuel problem may be to blame for the crashes, which left 89 dead.
But sources quoted by the Interfax news agency said that one plane before it crashed sent an emergency distress signal, often used to signal a hijacking, and that air traffic controllers had alerted police that the crew had been attacked.
The two Tupolev airliners - which disappeared from radar screens almost simultaneously - left the same terminal at a Moscow's Domodedovo airport 40 minutes apart, bound for different cities in southern Russia. Witnesses of the second crash reported hearing explosions.
President Vladimir Putin, vacationing in the Black Sea resort of Sochi - the destination of one of the planes - ordered Russia's Federal Security Service, successor to the KGB, to conduct the investigation.
Although officials say initial examination of the wreckage suggests no foul play, analysts say the timing of the twin crashes is too extraordinary to be a coincidence, and expect evidence to ultimately point to a terrorist act. If so, the attack would fit a surging pattern of violence that has thrown Kremlin policy on Chechnya into disarray since the head of the Moscow-backed Chechen regime, Ahmad Kadyrov, was killed in a May 9 bombing.
Wednesday, rebel spokesmen denied that guerrillas played any role in the plane crashes. "To us, any form of terrorism is absolutely unacceptable," Akhmed Zakayev, a spokesman for separatist leader Aslan Maskhadov, told Reuters in London. "We have condemned it and continue to condemn it." Still, experts note tough previous statements. In June, Mr. Maskhadov said rebels would "make changes in our tactics" and begin "launching big attacks."
In an e-mail exchange with Reuters a month ago, Maskhadov said that fighting beyond Chechnya in Russian territory was "absolutely legitimate." He added: "If Chechnya possessed warplanes or rockets, then air strikes on Russian cities would also be legitimate."
Guerrillas have also vowed to disrupt the vote next Sunday to elect as replacement president Mr. Putin's favored candidate, Alu Alkhanov.
"If we look at the situation from the moment [Kadyrov] was murdered, it shows the activity of rebels is growing, and even more that it is spreading [beyond Chechnya]," says Alexei Malashenko, a Chechnya expert at the Carnegie Moscow Center. "I think it is a new wave of military battle.... I'm afraid during the election in Grozny and across Chechnya, we will see a lot of things."
The continued violence in Russia's five-year war in Chechnya is an embarrassment for Putin, who has claimed repeatedly that life in the embattled republic is returning to normal.
Last Sunday, flanked by Mr. Alkhanov and Mr. Kadyrov's son Ramzan, Putin visited the late president's grave in Chechnya. But the mourning visit masks a renewed vulnerability in Chechnya for the Kremlin that appears to be growing.
The night before Putin's visit on Sunday, guerrillas staged a brazen attack against soldiers and Chechen police in Grozny, which reportedly left 42 dead.
If the twin plane crashes turn out to be terror attacks - following a wave of suicide bombings and other attacks the past two years, the October 2002 theater siege in Moscow, and Ingushetia raids in June that killed 58 - they will mark a further escalation.
"In the resistance camp, they feel that the Kremlin is vulnerable [and has] no good options - that the Kremlin is really desperate," says Pavel Baev, a Russia expert at the International Peace Research Institute in Oslo.
Growing attacks "not only hit targets and create a resonance," says Mr. Baev. "For the resistance, it's very important to prove they still exist, that they are capable of doing something, to attract new members and resources."
Throughout the war, human rights groups have charged Russian forces with severe abuses, including disappearances and executing prisoners.
Openness about embarrassing losses rarely comes quickly in Russia, and information about the plane crash may be no different. Officials were reluctant to finally acknowledge the loss of the Kursk nuclear submarine in August 2000; for weeks the loss was officially blamed on a foreign submarine, not mechanical failure.
"The Kremlin has to go forward with their election, and press on with their line, thought that doesn't prove it is a rational strategy, firm, and determined," says Baev. "It just shows they are trapped in this strategy...vulnerable as they are. Any sign of weakness would only increase the incentive for the resistance to strike again."
Does that mean that the current violence - and any possible Chechen link to the plane crashes - could yield a crackdown in Chechnya?
"Chechnya has been [in] crackdown so hard all these years, it's really hard to imagine how much harder [Russian forces] can crack," adds Baev. "What additional measures could they take?"
• Material from wire service reports was used in this article.