Here's what we know about the deadly Russian plane crash that killed all 224 people on board Saturday, Oct. 31. (Monica Akhtar/The Washington Post)

A Russian airliner carrying more than 200 passengers crashed in Egypt’s restive Sinai Peninsula, Egyptian and Russian officials said Saturday, prompting two major carriers to divert flights from the area after Islamic State militants said they downed the aircraft.

The move by Germany’s Lufthansa and Air France-KLM to avoid Sinai’s airspace underscored growing international concerns over the jihadists’ reach in the region, even as authorities and aviation experts dismissed the militants’ claims.

Egyptian and Russian officials on Saturday denied claims the jihadists shot down the plane, which had climbed to 31,000 feet before plummeting to the ground. Surface-to-air missiles can normally hit aircraft flying below 10,000 feet, analysts say.

The charter flight headed for the Russian city of St. Petersburg and operated by Russian carrier Metrojet “disappeared” shortly after takeoff from Egypt’s Red Sea resort of Sharm al-Sheikh, a popular destination for Russian tourists, Russia’s Federal Air Transport Agency said. It was carrying 217 passengers and seven crew members when it crashed into a remote region of central Sinai, the Egyptian Civil Aviation Ministry said. There were no survivors, Egyptian officials and Russia’s embassy in Cairo said.

Russian officials announced Saturday that they had opened an investigation for gross negligence and safety violations that may have led to the crash. In a statement, Russia’s Investigative Committee said it was searching the Moscow offices of the airline, Kogalymavia, which flies under the brand Metrojet, and the airline’s facilities at Domodedovo International Airport. Airline employees would be interviewed and the quality of fuel used by Metrojet on its flights would be examined.

Europe’s two largest airlines said they would not fly over Sinai, which is home to a violent Islamist insurgency, until investigators determined the cause of the crash. Islamic State’s Sinai affiliate claimed Saturday that its fighters downed the Airbus A320 to avenge Russian strikes on insurgents in Syria, but the group did not say how they brought down the plane.

Russia’s military intervened in Syria to bolster its ally and Syrian President Bashar al-Assad amid a devastating civil war. Russian warplanes have carried out hundreds of airstrikes and killed scores of civilians in Syria over the past month, rights group say. Egypt’s Sinai jihadists pledged allegiance to the Islamic State last year and have carried out hundreds of attacks on security forces. Security experts say the militants are known to have surface-to-air missiles that could take out low-flying aircraft.

The French-owned Airbus said in a statement that the crashed airliner was built in 1997 and had accumulated more than 56,000 hours of flight time. Metrojet acquired the plane in 2012, Airbus said.

Russian President Vladimir Putin expressed “his deepest condolences” to the families of those who died in the crash, the Kremlin press service reported, and ordered that Russian rescue workers be sent to the site of the crash. Putin also spoke to Egyptian President Abdel Fattah al-Sissi by telephone, a statement from Sissi’s office said Saturday. The leaders agreed to coordinate investigation efforts, the statement said.

In Egypt, military aircraft helped spot the wreckage Saturday morning. Search-and-rescue parties reached the crash site and began airlifting bodies to the Zeinhom morgue in central Cairo. Egypt’s Aviation Ministry said Saturday night that investigators had found the plane’s flight-data recorder.

Russian tourists flock to Egypt’s Sinai Peninsula every year, where temperatures remain high throughout the winter. The southern part of Sinai, along the Red Sea coast, is not plagued by the same Islamist violence in North Sinai, which borders the Gaza Strip. Holiday vacationers still head to South Sinai’s pristine beaches, but tourism has suffered from violence and turmoil in the wake of the Arab Spring.

Earlier this year, Egyptian Tourism Minister Khaled Abbas Rami said about 3 million Russian tourists traveled to Egypt in 2014, mostly to visit resorts along the Red Sea.

The Egyptian government said Saturday that among the passengers killed were three Ukrainian nationals. The remaining passengers were Russian citizens, including 17 children, authorities said.

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Today's coverage from Post correspondents around the world

Heba Habib in Cairo and Andrew Roth in Moscow contributed to this report.