The plane plunged into the Red Sea shortly after take-off from the resort of Sharm al-Shaikh early on Saturday, killing all 148 passengers on board.
The crash came as the US and Britain were on a heightened air security alert over fears that an airliner could be used for an 11 September-style attack.
Egyptian and French officials say there is no evidence that sabotage led to the Flash Airlines Boeing 737 crashing in the Egyptian red sea resort of Sharm al-Shaikh.
“The incident is absolutely not the result of a terrorist act, but is linked to a technical failure of the plane,” said Egyptian Foreign Minister Ahmad Mahir.
A tourism industry official said he was worried foreigners might cancel travel plans to Egypt during the peak season, even if the crash turns out to be an accident.
A French diplomat said a submarine robot had been brought in to aid the search for the remains of the mainly French tourists killed in the crash.
“A submarine robot capable of operating in depths of 400 metres (1,300 feet) arrived this morning from France,” said naval attache Commander Xavier de Sontenay.
The frigate Le Tourville was also heading north from a French base in Djibouti to help the search and was expected to arrive on Monday, he said.
The robot was already “operating beneath the crash area to try to locate debris or victims.”
Rescue workers gather wreckage
State television showed Egyptian air force planes, navy ships and a helicopter searching the sea.
By late evening on Saturday, rescue workers had recovered remains of the bodies of six people, according to French junior foreign minister Renaud Muselier, who was dispatched to Egypt by President Jacques Chirac.
Egyptian Civil Aviation Minister Ahmad Shafik said rescue workers had also recovered sections of the plane wreckage, while local television showed pictures of debris floating in the sea, including tattered, bright yellow life-jackets.
A hospital in Sharm al-Shaikh became the focus of anger when it was turned into an emergency morgue for some of those who died.
“They tell us there are only pieces of flesh placed inside and that we will not be able to identify anyone,” said Hatim al-Qaliubi who had lost a relative in the crash.
Flight 604 to Paris via Cairo disappeared from radar screens at 4:44 am (0244 GMT), minutes after taking off from the popular resort on the southern tip of the Sinai desert.
“The plane had a problem at take-off and then tried to turn around, and it was at that moment that it apparently crashed,” said junior French transport minister Dominique Bussereau.
Radar readings showed the doomed charter flight climbed to 5000 feet after take-off and made a planned left turn before engaging in an unusual manoeuvre and plunging into the sea, Shafik said.