25 August 2004 -- Russia's Federal Security Service (FSB) is investigating two separate Russian plane crashes that killed about 90 people.
Investigators say the two crashes that occurred nearly at the same time could have been a freak coincidence, but could also have been a terrorist attack.
FSB spokesman Sergei Ignatchenko says investigators are now examining several possible causes for the crashes.
"Several [possible causes of the plane crashes] are being considered. The main version is a violation of civil aircraft regulations. A terrorist act is also being considered as a possible cause, but there has been no evidence found up to this moment that it was a terrorist act," Ignatchenko said.
The first jet went down in the Rostov region some 1,000 kilometers south of Moscow about three minutes before a second jet crashed in the southern Tula region. Both planes took off within an hour of each other from the same Moscow airport.
Thunderclaps and rain showers were reported in both regions.
Uncertainty over the crashes came after an airline official said one of the jets had activated a distress signal shortly before disappearing from radar screens.