Russian emergency workers searched heaps of twisted metal and tall grass Wednesday for clues about what caused two airliners to plunge to earth within minutes of each other, killing all 89 people aboard. Officials said one jet sent a hijack distress signal, raising fears terrorists had struck.

Russia investigates twin plane crashes

Flight recorders from both planes were found and taken to Moscow for investigation, ITAR-Tass reported, indicating the question of what caused the twin disasters soon could be answered.

Russian security authorities said that explosives specialists were still working at the scene of the crashes. They reported that terrorism remained a possible cause, although there was no evidence so far that terrorists were behind the tragedies.

Federal Security Service spokesman Sergei Ignatchenko said investigators were still questioning airport officials and airline and security employees at Domodedovo Airport, from which both flights left 45 minutes apart.

The airport on Moscow's far south side operates a single terminal that serves both international and domestic flights. Both flights were serviced at and left from the domestic section.

Security tightened at airports in Russia after plane crash (3)

The service, known as the FSB, is a successor agency to the KGB. Officials there said they were investigating other possibilities such as technical failures, the use of poor quality fuel, breaches of fueling regulations and pilot error. Rain and thunder was reported in the regions where both crashes occurred.

Rebels fighting a protracted war for independence for Chechnya, the troubled southern Russian province, have been blamed for a series of terror strikes that have claimed hundreds of lives in Russia in recent years. But rebel representative Akhmed Zakayev told Russia's Ekho Moskvy radio from London that Chechen forces and rebel leader Aslan Maskhadov were not connected to the crashes.

Russian officials had expressed concern that separatists in the war-ravaged republic might carry out attacks ahead of a regional election Sunday to replace its pro-Moscow president who was killed in a May bombing.

Source: Moscow Times