Just In: Russian plane crashes in Sinai, reportedly killing all 224 people on board.

Cairo (CNN)A Russian passenger airliner crashed early Saturday in the Sinai Peninsula, with 224 people aboard, officials said.

All passengers were killed, the Russian Embassy in Cairo said on Twitter.

Russian state media reported that many of the 217 passengers were Russians returning from vacation. The passengers were reported to include 17 children. There were seven crew members.

The plane had departed the Red Sea resort of Sharm el-Sheikh in the Sinai on a flight to St. Petersburg, Russia.

                                       

Here's what we are learning as the day wears on:

• Al-Ahram, an Egyptian state-run newspaper, quoting medical sources, reports that 100 intact bodies have been recovered and are being prepared for transfer to a morgue in Cairo, but other bodies are in pieces. The recovery of 100 bodies this quickly from a smoldering wreck seems highly unlikely, however.

Relatives react at the St. Petersburg, Russia, airport after news of the crash.

• Bodies of plane crash victims are being recovered from the crash site, the Russian Embassy in Cairo says on its official Twitter account.

• An Egyptian investigation team has reached the crash site of the crashed jet in Egypt's Sinai Peninsula, state-run Nile TV reports, citing the minister of civil aviation.

• Airbus, the plane's maker, issues a statement on Twitter: "We are aware of the media reports," the tweet reads. "Efforts are now going towards assessing the situation. We'll provide more information as soon as available."

Russian investigation ordered

• Russian President Vladimir Putin declares an official day of mourning Sunday for victims of the crash, the Kremlin says. And he is ordering Prime Minister Dmitry Medvedev to open an investigation into the crash.

• The Northern Sinai medical department declares a state of emergency, according to Al-Ahram. The Prime Minister's office reports that 50 ambulances have been dispatched to the area, which is mountainous.

• The Russian emergency ministry will send five planes to the area to help with possible rescues and the investigation. Russia has opened a hotline for relatives, many of whom have already gathered at the airport in St. Petersburg.

• Russia 24, a state-owned news channel, and other Russian media outlets are saying the pilot reported technical problems and requested a landing at the nearest airport before the plane went missing. Officials have not corroborated those reports.

• Russia 24 also quotes the FlightRadar 24 website as saying the plane was descending at a rate of 1,800 meters per minute, or 67 mph, before radar contact was lost.

• Weather in the area was clear, CNN reports.

• The Egyptian Prime Minister meets with ministers and security officials regarding the crash. An ISIS-aligned insurgency is active in parts of Sinai, but there is no initial indication it played any role in the crash.

Plane was at 31,000 feet when contact was lost

• The crash site is in the northern part of Sinai, near a town called Housna -- 300 kilometers (185 miles) from the Red Sea resort of Sharm el-Sheikh, the Egyptian Prime Minister's office says Egyptian air force planes have spotted the crash site from the air, officials say.

• Two-hundred twenty-four people were reported to be aboard, including 217 passengers and seven crew members. The passengers include d17 children. The Belarus Ministry of Foreign Affairs said its embassy in Egypt is working to determine whether Belarusians were on board.