PARIS: Black box data from the Russian plane that crashed in Egypt last week indicates it was hit by a bomb, sources said, before an Egypt-led probe into the disaster was set to release its first findings Saturday.

Both the flight data and voice recorders failed 24 minutes after the plane took off from the Sharm el-Sheikh resort en route to Saint Petersburg, when it plummeted from the sky into the Sinai Peninsula killing all 224 people on board.

Cairo and Moscow initially dismissed a claim self-styled Islamic State (IS) militants downed the plane, but growing evidence it was attacked has prompted several countries to warn against travel to Sharm el-Sheikh.

On Friday, Russian President Vladimir Putin also ordered flights to the Red Sea resort halted, in a fresh blow to Egypt's already struggling tourism industry.

Kremlin spokesman Dmitry Peskov told news agencies the measure did not mean Russia believed the crash — the worst aviation disaster in Russia's history — was due to an attack, and the investigation continued.

The head of Russia's emergencies ministry said Russian experts had taken samples from the crashed jet and were testing it for any traces of explosives.

But a source close to the investigation told AFP the black box data "strongly favours" the theory a bomb on board brought down the plane.

Another person close to the case in Paris said the plane had suffered "a violent, sudden" end, saying: "Everything was normal during the flight, absolutely normal, and suddenly there was nothing."

Egyptian Aviation Minister Hossam Kamal and the head of the Egypt-led investigation into the disaster are due to hold their first news conference at 1500 GMT on Saturday, although the government warned it could be delayed.

Security was horrendous

Egyptian President Abdel Fattah al-Sisi's office said he called Putin and they agreed to bolster coordination to "strengthen security measures for Russian planes."

With international concerns mounting, European airlines prepared to bring home thousands of tourists from the Red Sea resort, which has been a jewel in Egypt's tourism crown.

Denmark on Friday became the latest European country to warn against travelling to Sharm el-Sheikh, following France, Belgium and Britain, while several airlines have banned check-in luggage as a precaution.

Read: Russia, Egypt dismiss US, UK claims bomb brought down jet

The US said it would also step up security screenings of US-bound flights from some Middle East airports as a precaution.

There were angry scenes in Sharm el-Sheikh, as thousands of anxious Britons, who had also hoped to fly home, were sent back to their hotels after Egypt blocked several other repatriation flights.

“I think a lot of people will question whether they ever want to go to Egypt again,” Emma Turner, a 34-year-old from southeast England, said after arriving back in London.

Eight flights carrying some 1,400 travellers returned to Britain on Friday after restrictions were lifted, but tourists were only allowed to bring carry-on bags.

Kamal said only eight of 29 flights could take off because the airport could not cope with all the luggage left behind.

Russia's Interfax news agency quoted a representative of national carrier Aeroflot saying a plane would be sent Friday to pick up stranded Russians.

Tourism industry hit

IS said it downed the plane in retaliation for Russian air strikes in Syria, but has provided no details as to how.

If it was behind the attack, it would be the first time the militants, who control large areas of Syria and Iraq, have hit a passenger plane.

United States President Barack Obama has said that Washington was "seriously" considering the possibility of a bomb aboard the plane, while British premier David Cameron told reporters it was "more likely than not that... a terrorist bomb" caused the crash.

Egypt has beefed up security at airports to "give confidence to the British government, but that does not mean we concur with any scenario", foreign ministry spokesman Ahmed Abu Zeid said.

The crash has the potential to deeply damage Egypt's tourism industry, still struggling to recover from a turbulent four years following its 2011 revolution.

Once a remote beach on the edge of the Red Sea, Sharm el-Skekh has grown into the jewel of Egypt's tourism industry, with dozens of luxury hotels and night life attracting tourists from around the world.

The town attracted on average three to four million tourists a year before the 2011 popular uprising that ousted longtime president Hosni Mubarak.

Also read: Plane crash: Obama finds bombing claim plausible