Two airport workers have been arrested in Sharm el Sheikh on suspicion of helping those responsible for the attack on Metrojet Flight 9268.
Egyptian security officials say they detained two employees of Sharm el Sheikh International Airport accused of having links to the attack.
The arrests follow confirmation from Russia that last month's crash, which killed 224 people, was caused by a terrorist act.
The Federal Security Service (FSB) said a bomb went off on the plane, causing it to crash in the Sinai Peninsula on 31 October.
"One can unequivocally say that it was a terrorist act," the head of the FSB, Alexander Bortnikov, said.
The FSB added that traces of explosives were found in debris at the crash site.
A $50m (£33m) reward has been promised for information that leads to the arrest of those responsible for the bombing, according to the Interfax news agency.
Russia's President Vladimir Putin has ordered special services to focus on finding those responsible for bringing down the plane.
The Metrojet airliner crashed shortly after taking off from Egypt's Sharm el Sheikh International Airport.
All 224 people aboard the Airbus A321 died.
Both US and British intelligence pointed towards a terrorist act in the immediate aftermath of the crash.
A member of the investigation team said they were "90% sure" that a noise heard on the black box was a bomb.
Thousands of Britons were stuck in Sharm el Sheikh in the days after the crash as the UK, Russia and several other countries suspended flights to and from the popular tourist destination.
Tourist operators were forced to scramble to get frustrated holiday-makers back to Britain.
(Sky News)