Search and rescue team members are still gathering the remains of victims after the crash on Saturday, the sources said.
The plane was heading to St Petersburg, likely carrying tourists returning from holidays in Egypt’s popular Sharm el-Sheikh resort.
The Russian embassy confirmed there were no survivors.
In a statement, Egypt’s civil aviation ministry said the wreckage of the Russian passenger jet was found in the Hassana area, south of the city of el-Arish.
It said the plane – a Metrojet Airbus A321 – took off from the Sinai Peninsula’s Sharm el-Sheikh, a popular destination for Russian tourists, and disappeared from radar screens 23 minutes after takeoff.
Day of mourning
Among the passengers were 214 Russians and three Ukrainians, plus seven crew members, the Egyptian government said.
At least 24 children were on board, the Association of Travel Operators of Russia said.
Russian President Vladimir Putin declared a day of national mourning.
Many bodies had already been found, said Mahmoud al-Zanati, head of the Egyptian Civil Aviation Authority.
“The search operation is still going on at the site of the accident. The wreckage is spread across a vast area,” he added, according to state-run newspaper, al-Ahram.
“A tragic scene”
Egyptian rescue team members earlier said they heard voices in a section of the plane, an officer on the scene told Reuters news agency.
North Sinai security sources said a technical fault caused the crash.
The flight recorder which contains the flight data was also found at the scene.
An Egyptian security officer at the scene said: “A lot of the dead are on the ground, and many died whilst strapped to their seats. I now see a tragic scene.
“The plane split into two, a small part on the tail end that burned and a larger part that crashed into a rock. We have extracted at least 100 bodies, and the rest are still inside.”
At a hotel near St Petersburg’s Pulkovo airport, the friends and relatives of those on the flight gathered to grieve.
Yulia Zaitseva said her friends, a newlywed couple named Elena Rodina and Alexqander Krotov, were on the flight. Both were 33 years old.
Zaitseva said that her friend “really wanted to go to Egypt”.
She added: “We were friends for 20 years. She was a very good friend who was ready to give everything to other people. To lose such a friend is like having your hand cut off.”
Separately, Egypt’s top prosecutor ordered an investigation into the cause of the crash.
Nabil Sadek, the prosecutor general, ordered the formation of a team of prosecutors tasked with going to the site of the crash and investigating the debris.
A centre to help relatives of the passengers has been set up at the Pulkovo airport, Tass news agency quoted St Petersburg city officials as saying.
The Airbus 321 was at an altitude of 9,450m when it vanished from radar screens.
Most of the passengers are said to be Russian tourists, according to reports. The plane was operated by the small Russian airline Kogalymavia, based in western Siberia.
The pilot reportedly requested clearance for an emergency landing at Cairo airport due to a technical malfunction.