"The third stage of the rescue operation is planned for tomorrow. The search area will be expanded to 30 square kilometres. And I ask for plans to be presented to the national centre before midnight. French experts from Airbus will proceed with work on the crash site, as well as representatives of the Interstate Aviation Committee and Egypt's aviation authorities."

　　Discussing the cause of the tragedy, many analysts believe that an external factor could have caused the air disaster, such as a purely mechanical or physical action.

　　But Russian aviation authorities said it was premature to comment on the possible cause, and said the conclusions can be drawn only after the fragments and contents of the black boxes have been studied.

　　The plane's flight data and cockpit voice recorders have both been recovered from the crash site.

　　俄罗斯继续搜寻空难遇难者

　　Talking about comments saying that the Islamic Group may hit the plane down, Gerald Feldzer, a Paris-based aviation expert, denied that explanation, saying the IS group has neither the equipment nor skills to bring down an airliner.

　　Gerald, however, also suggests that it is "absolutely a possibility" that a bomb was smuggled into the hold of the plane.

　　"One thing is sure: If such a violent and sudden accident occurred, it might have been due to an engine explosion that could have set fire to the wing and led to the loss of control of the plane, which would have spun into a nosedive. Or, it also could have lost a part of its rudder. We can imagine this scenario but we can also imagine that the pilot in this situation would have sent a mayday distress signal since he was in contact with the control tower."

　　Meantime, relatives of victims continue to arrive at a crematorium in the Russian city of St' Petersburg, with more bodies of the victims are expected to arrive in the city.

　　Officials say 130 bodies and 40 body parts arrived earlier, and latest reports show that 4 bodies have been identified so far.

　　Saturday's crash killed all 224 people aboard the plane, which was headed from the Red Sea resort of Sharm el-Sheikh to St. Petersburg.

　　For CRI, I'm Xie Cheng.