Cairo: Investigators began their examination on Tuesday of the two black boxes from the Russian airliner that crashed in Egypt's Sinai Peninsula.
The examination of the black boxes - one which recorded on-board conversations and the other flight data of the Airbus A321 that crashed on Saturday killing all 224 people on board - started around midday (1530 IST), an Egyptian civil aviation ministry official told AFP.
The probe could last several weeks or months if the recordings in the black boxes have been damaged, sources said. Russia's government commission overseeing the investigation was also due to meet today.
The Saint Petersburg-bound plane operated by Russian airline Kogalymavia crashed 23 minutes after taking off from the Red Sea resort of Sharm el-Sheikh.
Most of the passengers were Russian tourists.
Kogalymavia said the plane crashed due to "external action," and that there was no technical fault or human error. It insisted the aircraft was in an "excellent technical condition".
Within hours of the crash, the Egyptian affiliate of IS based in the Sinai claimed it had downed the jet in retaliation for Russian air strikes targeting fellow jihadists in Syria.
Yesterday, US Director of National Intelligence James Clapper said it was "unlikely" that IS was involved in the Kogalymavia plane crash but did not rule out the possibility.
Alexander Neradko, head of Russia's aviation authority, criticised the airline's comments ruling out technical fault or human error, saying they were "premature and not based on any real facts".
Cairo, Moscow and Washington have downplayed the IS claim, although analysts have not ruled out that a bomb may have been planted on board.
Experts say the fact that debris and bodies were strewn over a wide area points to a mid-air disintegration of the aircraft unlike most air crashes.