Update 13.45pm

* Flight MS804 missing soon after entering Egyptian airspace

* Airbus A320 carrying 56 passengers, 10 crew

* Debris, suitcases and body parts found 290km north of Alexandria

* Cause remains unknown, but Egypt's Aviation Minister says terrorism is the more likely cause 

* 30 Egyptians, 15 French, 10 other nationalities aboard flight

Debris from the wreckage of the missing EgyptAir plane that disappeared yesterday has been found 290 kilometers north of the Mediterranean coastal city of Alexandria, the Egyptian army has said. 

Navy officials have also found some of the passengers' belongings and they are sweeping the area looking for the plane's black box, the military said in a statement.

Greece's Foreign Minister subsequently said that search crews had found a body part, seats and one or more items of luggage from the plane. 

The discovery comes after Egyptian officials last night retracted earlier statements that parts of the plane had been found at sea. 

EgyptAir told CNN that what they originally thought to have been debris was not in fact part of their missing plane, confirming statements made by Greek officials earlier yesterday. 

The EgyptAir jet carrying 66 passengers and crew from Paris to Cairo disappeared from radar at 2.30am on Thursday morning in what Egypt has said could have been a terrorist attack.

Egyptian Prime Minister Sherif Ismail said it was too early to rule out any explanation for the crash, including an attack like the one blamed for bringing down a Russian airliner over Egypt's Sinai Peninsula last year.

The country's aviation minister said a terrorist attack was more likely than a technical failure. The New York Times this morning quoted the head of Greece's air safety board ruling out mechanical failure as a cause of the crash. 

But French officials this morning refused to be drawn into speculating what had caused the plane to disappear, with French Foreign Minister Jean-Marc Ayrault saying they had "absolutely no indication" of what caused the crash. 

Greece has deployed aircraft and a frigate to search for the missing Airbus. Egypt has said it will lead the investigation and France would participate. Three French investigators arrived in Cairo early this morning, Reuters reported.

READ MORE: Egypt mobilises army, navy for search

In Washington, President Barack Obama received a briefing on the disappearance from his adviser for homeland security and counter-terrorism, the White House said. A White House spokesman said it was too early to know the cause of the crash and offered condolences to the victims.

Greek Defence Minister Panos Kammenos said the Airbus swerved 90 degrees to the left, spun through 360 degrees to the right and plunged from 37,000 feet to 15,000 before vanishing from Greek radar screens.

According to Greece's civil aviation chief, calls from Greek air traffic controllers to flight MS804 went unanswered just before it left Greek airspace, and it disappeared from radar screens soon afterwards.

There was no official indication of a possible cause, whether technical failure, human error or sabotage. Ultra-hardline Islamists have targeted airports, airliners and tourist sites in Europe, Egypt, Tunisia and other Middle Eastern countries over the past few years.

The aircraft was carrying 56 passengers - with one child and two infants among them - and 10 crew, EgyptAir said. They included 30 Egyptian and 15 French nationals, along with citizens of 10 other countries.

Asked if he could rule terrorist involvement, Prime Minister Ismail told reporters: "We cannot exclude anything at this time or confirm anything. All the search operations must be concluded so we can know the cause."

French President Francois Hollande also said the cause was unknown. "No hypothesis can be ruled out, nor can any be favoured over another."

"LIVES ARE SO CHEAP"

At Cairo airport, a man sat on a brown leather couch crying with his hands covering his face. "How long will Egypt live if human lives are so cheap?" he said.

The mother of a flight attendant rushed out of the VIP hall where families waited in tears. She said the last time her daughter called her was Wednesday night. "They haven't told us anything," she said.

Some relatives tried to beat up a photographer working for EgyptAir who took several pictures of the families waiting in the hall. Security officials intervened and escorted him out.

With its archaeological sites and Red Sea resorts, Egypt is a traditional destination for Western tourists. But the industry has been badly hit by the downing of a Russian Metrojet flight last October, in which all 224 people on board were killed, as well as by an Islamist insurgency and a string of bomb attacks.

A320s normally seat 150, which means the Egyptair plane was barely a third full.

Greek air traffic controllers spoke to the pilot as the jet flew over the island of Kea, in what was thought to be the last broadcast from the aircraft, and no problems were reported.

But just ahead of the handover to Egyptian controllers, calls to the plane went unanswered.

"About seven miles before the aircraft entered the Cairo airspace, Greek controllers tried to contact the pilot but he was not responding," said Kostas Litzerakis, head of Greece's civil aviation department. Shortly after exiting Greek airspace, it disappeared from radars, he said.

Greek authorities were searching the sea south of the island of Karpathos, Defence Minister Kammenos told a news conference.

"At 3:39 a.m. (0039 GMT), the course of the aircraft was south and southeast of Kassos and Karpathos (islands)," he said. "Immediately after, it entered Cairo FIR (flight information region) and made swerves and a descent I describe: 90 degrees left and then 360 degrees to the right."

Egyptian Civil Aviation minister Sherif Fathi said authorities had tried to resume contact but without success. Greece said it would scale back its rescue effort because the finds were in waters under Egyptian jurisdiction.

In Paris, a police source said investigators were now interviewing officers who were on duty at Roissy airport on Wednesday evening to find out whether they heard or saw anything suspicious. "We are in the early stage here," the source said.

Airbus said the missing A320 was delivered to EgyptAir in November 2003 and had operated about 48,000 flight hours. The missing flight's pilot, who EgyptAir named as Mohamed Said Shoukair, had clocked up 6,275 hours of flying experience, including 2,101 hours on the A320, while the first officer, Mohamed Mamdouh Ahmed, had 2,766 hours.

Adam Schiff, the top Democrat on the U.S. House Intelligence Committee, said no conclusions could be drawn yet but terrorism was a very possible cause.

"If terrorism was indeed the cause, it would reveal a whole new level of vulnerability to aircraft - not only from those flights originating in the Middle East, but to those departing from the heart of Europe and with, at least in theory, far better airport defences," he said.

Other countries offered to help in the investigation, including the United States, where engine maker Pratt & Whitney is based.

Russia and Western governments have said the Metrojet plane that crashed on Oct. 31 was probably brought down by a bomb, and the Islamic State militant group said it had smuggled an explosive device on board.

That crash called into question Egypt's campaign to contain Islamist violence. Militants have stepped up attacks on Egyptian soldiers and police since Sisi, then serving as army chief, toppled elected president Mohamed Mursi, an Islamist, in 2013 after mass protests against his rule.

In March, an EgyptAir plane flying from Alexandria to Cairo was hijacked and forced to land in Cyprus by a man with what authorities said was a fake suicide belt. He was arrested after giving himself up.

EgyptAir has a fleet of 57 Airbus and Boeing jets, including 15 of the Airbus A320 family of aircraft, according to airfleets.com.

You will find more statistics at Statista

In Cairo, Mr el-Sissi convened an emergency meeting of the National Security Council, the country's highest security body. The council includes the prime minister and the defence, foreign and interior ministers, in addition to the chiefs of the intelligence agencies.

In Paris, relatives of passengers on the flight started arriving at Charles de Gaulle Airport outside the French capital, where their loved ones were last seen alive.

The Airbus A320 is a widely used twin-engine, single-aisle plane that operates on short and medium-haul routes. Nearly 4,000 A320s are currently in use around the world. The ubiquity of the A320 means the plane has been involved in several accidents over the years. The last deadly crash involving the plane was Germanwings Flight 9525, in which all 150 on board died when one of the pilots intentionally crashed it in the French Alps.

Airbus said the aircraft was delivered to EgyptAir in 2003 and had logged 48,000 flight hours before it "was lost" over the Mediterranean. The European plane-maker said in a statement that it had engines made by Swiss-based engine consortium IAE, and had the serial number 2088.