Egypt plane crash investigators "90% sure" the explosion heard on the black box recording of the Russian flight was a bomb, a member of the investigation team told Reuters.
A memorial service for the 224 victims of the crash was be held in St Petersburg today.
Investigators analysing evidence taken from the crash site of a Russian passenger plane that went down in Egypt, killing 224 people, say a "noise was heard in the last second" of a recording taken from one of the flight's black boxes.
The Egyptian Civil Aviation Minister told a press conference: "There was a noise that was heard at the last second of the CVR which would require that spectral analysis will be conducted in specialised laboratories in order to identify the nature of the sound."
According to the minister investigators are still at the "stage of data collection" and "are attaching importance to all the possible scenarios" as they continue to try to identify the cause of the crash.
The investigations committee is made up of 47 investigators, including 29 experts from Egypt, seven from Russia, six from France, two from Germany, and three from Ireland, as well as 11 accident advisers.
Terrorists would be able to bypass the wand-like devices being used to scan luggage in Sharm el-Sheikh, an expert has claimed.
Intelligence showed a "significant possibility" that the crashed Russian passenger jet was brought down by an explosion, ITV News was told.
As flights from Sharm el-Sheikh to the UK are delayed over bomb fears, we review what is known about the Egyptian plane crash tragedy.