The aircraft manufacturer Airbus says, external in a statement that it "regrets to confirm the loss of an EgyptAir A320".

It adds that the aircraft involved, registered as SU-GCC, was delivered to EgyptAir from the production line in November 2003. The aircraft had accumulated approximately 48,000 flight hours and was powered by IAE engines. 

A320s first entered service in 1988. At the end of April 2016 more than 6,700 A320 aircraft were in operation worldwide, according to Airbus. To date, the entire fleet has accumulated almost 180 million flight hours in over 98 million flights.

The BBC has been in contact with a team at the Department of Physics at the University of Oxford - a Nasa satellite it uses was over the Mediterranean at the time the flight disappeared.

Image source, Nasa/University of Oxford

As you can see from this image, the skies were clear at the time. BBC Weather reported there were no storms in the region.

Oxford University researcher Simon Proud told the BBC there did not appear to be smoke in the area.

In a statement on its Facebook page, EgyptAir says inaccurate information is doing the rounds.

Image source, Facebook

It is not clear what "misleading information" the company is referring to. Earlier, EgyptAir distributed a statement saying a distress signal was received by the Egyptian military at 04:26 local time (03:26 BST), more than an hour-and-a-half after the flight disappeared from radars. The comments were widely reported, but Egypt's military has since denied a signal was received.

A Greek aviation source has told the AFP news agency that the missing EgyptAir plane crashed into the sea off the southern Greek island of Karpathos at about 01:30 BST.

AFP are the only news outlet to report this so far.

Hugh Schofield
BBC News, Paris

Image source, Reuters

If this turns out to be a terrorist attack, then eyes will turn first of all to Charles de Gaulle airport, from where Flight MS804 took off on Wednesday night. Could there have been a breach of security allowing a device to be smuggled on board?

Security at Charles de Gaulle, already tight, has been tightened even further in recent months, after the Paris attacks in January and November. There is the visible security – soldiers on patrol – but more important is what is not seen: monitoring of passengers and staff.

One weak point identified in recent years has been the large number of flight-side workers who come from high-immigrant areas of the Paris suburbs. Last year there was a security review of the 86,000 workers with authorisation to go flight-side. More than 60 had their authorisation withdrawn because of fears of Islamic radicalisation.

Of course investigation will also look at other possibilities: that the device (if there was one) was smuggled on elsewhere.

The website MarineTraffic has posted a short video showing how ships are rushing to the area where the plane disappeared - it looks like plenty of traffic is heading there from Egypt and the Greek island of Crete.

Image source, AirTeamImages

This is an image we have just received of the Airbus A320-232 plane, registration SU-GCC, that has gone missing.

Egyptian state TV's correspondent at Cairo International Airport quotes Prime Minister Sherif Ismail as saying there are no confirmed reports so far on the current situation of the EgyptAir plane, according to BBC Monitoring. 

Speaking to reporters at the airport this morning, Mr Ismail said it was too early to speak about what really happened to the plane. A news conference on the incident would be held after 13:00 local time (12:00 BST), he added.

In the past hour, EgyptAir said on its Twitter account that a distress signal had been received by Egypt's military from flight MS804 (though it is unclear whether they meant an automated signal or a manual one).

Now, Egypt's military, in a statement, says no such signal was received. We'll bring you more on that as we get it.

The families of those on board are being kept inside the EgyptAir in-flight service building at Cairo International airport. EgyptAir says a number of doctors and translators are being provided.

Image source, Associated Press

Reuters is now reporting comments by Greece's air traffic controllers, who say they spoke to the pilot of flight MS804 over the island of Kea.

It's thought this was the last broadcast from the aircraft.

"The pilot did not mention any problems," Kostas Litzerakis, head of Greece's civil aviation department, told Reuters.

It exited Greek airspace at 03:27 local time (01:27 BST) and entered Cairo airspace. Two minutes later it vanished from Greek radars, Mr Litzerakis said.

Egypt's al-Ahram newspaper tweets:

The newspaper says the pilot's name is Mohammed Shokeir, and that he had more than 6,000 hours of flying experience. His co-pilot had more than 2,000 hours in the air.

No other news outlets have yet named the pilot.

In a series of tweets, EgyptAir confirms a distress call was received from flight MS804 - it then despatched search teams at about 04:26 Cairo time.