Russian plane crash is an internal factor.

The Russian plane that crashed in Egypt was not struck from the outside and the pilot did not make a distress call before it disappeared from radar, a source in the committee analysing the flight recorders said
on Monday.

The source declined to give more details but based his comments on the preliminary examination of the black boxes recovered from the Airbus A321 which crashed in the Sinai Peninsula on Saturday killing all 224 people on board.

A civil aviation source said only that Egyptian investigators aided by Russian and French experts had not yet finished examining the black boxes.

Russian officials have said the plane, carrying holidaymakers from the Red Sea resort of Sharm el-Sheikh to St Petersburg, likely broke up in mid-air but said it was too early to say what caused it to crash.

The first bodies recovered from the wreckage arrived on board a Russian government plane at St Petersburg’s Pulkovo Airport, where grieving Russians left piles of flowers.

A Reuters photographer saw a white lorry leaving the airport, escorted by police cars, heading for a St Petersburg morgue, where the bodies were to be identified.

Russian news agencies said the plane carried 144 bodies and a second government plane was due to leave Cairo on Monday evening.

Russian President Vladimir Putin, who had declared Sunday a national day of mourning, said on Monday the crash was a great tragedy.

“Without any doubt everything should be done so that an objective picture of what happened is created,” Putin said in comments cited by ITAR-TASS. “So that we know what happened.”

When asked if a terrorist attack could be to blame, Putin’s spokesman Dmitry Peskov said no theory could yet be ruled out.

An Egyptian militant group affiliated with Islamic State said on Saturday it brought down the plane “in response to Russian air strikes that killed hundreds of Muslims on Syrian land”. Russia’s transport minister dismissed the claim, saying it “can’t be considered accurate”.

Alexander Smirnov, deputy general director of airline Kogalymavia, which operated the plane under the brand name Metrojet, said only a “technical or physical action” could have caused the aircraft to break up in the air.

“The plane was in excellent condition,” Smirnov told a news conference in Moscow. “We rule out a technical fault and any mistake by the crew.”