It's being reported that investigators looking into the crash are "90 percent sure" a noise heard on one of its black box recorders was an explosion caused by a bomb.
The Russian government says it's brought home 11 thousand of its citizens from Egypt in the last 24 hours.
All 224 people on board the plane died when it crashed in Sinai.
Reporter Alex Rossi is in Sharm el-Sheikh in Egypt:
Meanwhile, a memorial service has been held in St Petersburg for the victims of the crash.
Cathedral bells at St. Isaac's tolled 224 times in memory of each person killed.
(Image: @RT_com)
