Prosecutor-General Vladimir Ustinov on Wednesday told Russian President Vladimir Putin that he had no clear view of what happened to the planes, which took off from Moscow’s Domodedovo airport late on Tuesday around an hour apart for two different destinations.
The two planes crashed within four minutes of each other.
“We are examining a number of versions, among them a terrorist act, and human and technical factors,” Ustinov told Putin.
Acting swiftly before Sunday’s presidential poll in the breakaway republic of Chechnya, President Putin has ordered the tightening of security at all Moscow’s airports and put the Interior Ministry in charge of screening procedures.
A Tu-134 flying to Volgograd went down near the town of Tula south of Moscow. Within minutes and 800km away, a Tu-154 bound for the Black Sea resort of Sochi crashed near the southern town of Rostov-on-Don.
The owner of the Tu-154, Sibir Airlines, said the pilots had triggered a hijack alert just before their plane crashed and the aircraft seemed to have exploded in mid-air. It was carrying 46 passengers and crew.
“We are examining a number of versions, among them a terrorist act, and human and technical factors"
The owners of the ill-fated Tu-134 said the crew did not report any problems on board before the plane crashed with 43 passengers and crew.
Aided with cranes, investigators sieved through high grasses in almost identical countryside near the two crash sites.
With the presidential poll in Chechnya in mind, analysts said the chance of two planes crashing within minutes must have been more than a coincidental malfunction.
Chechen separatist fighters have vowed to disrupt the polls.
“It’s freaky if it is not sabotage,” said David Learmount, safety editor at Flight International magazine.
Moderate Chechen separatists have meanwhile denied complicity.
“Of course not,” insisted Akhmed Zakayev, a spokesman for Chechen separatist leader Aslan Maskhadov, when asked if his group was responsible for the crashes.