Updated | Egyptair flight 804 still surrounded by mystery

Egypt's army spokesman said wreckage and passenger belongings were found 290km off the coast of Alexandria in Egypt.

Greek, Egyptian, French and UK military units have been taking part in a search operation near Greece's Karpathos island.

Greece said radar showed the Airbus A320 had made two sharp turns and dropped more than 7,620m before plunging into the sea.

Egypt says the plane was more likely to have been brought down by a terrorist act than a

Three investigators from the French air accident investigation bureau, along with a technical adviser from Airbus, have joined the Egyptian inquiry.

After it was confirmed that the flight had not landed in any nearby airport, a huge hunt was launched in the Mediterranean for debris from the EgyptAir jet that swerved abruptly and disappeared from radar while carrying 66 people from Paris to Cairo.

EgyptAir initially claimed debris and life jackets belonging to MS804 had been found near the Greek island of Karpathos, east of Crete, but airline vice-president Ahmed Adel later retracted the statement, saying the recovered debris “is not our aircraft”.

Greece had sent a frigate to the area on Thursday but, since then, deputy spokesman of the Hellenic National Defense General Staff, Marius Tzannis told CNN that Greek ships are no longer participating in the search.

Tzannis added that Greek coastguard vessels o not have the capacity to operate so far away from the coast. Furthermore, Egyptian officials are leading the search operations because they are taking place in an area which, by law, falls under Egyptian control.

According to Tzannis, despite pulling the warships back, Greece still has a C-130 aircraft operating in the area and several others on standby in Crete and Karpathos island, including “an appropriate number” of F-16s.

The US navy also dispatched a P-3 Orion maritime surveillance aircraft from a base in Sicily, but retrieving the plane’s black box is likely to be a long and fraught operation.

Speaking to the Guardian, the head of Greece’s air traffic control board, Serafeim Petrou, said it was a “fact the plane had crashed”, adding that “most probably, and very unfortunately, it is at the bottom of the sea.”

Petrou said tracing the cause and retrieving wreckage would therefore take time. “Nothing can be excluded. An explosion could be a possibility but, then, so could damage to the fuselage,” he said.

What happened to the plane is still unknown, and authorities up to this point can only speculate.

No group has claimed responsibility for downing the aircraft and Egypt’s aviation minister, Sherif Fathi, said he did not want to prematurely draw conclusions, but added: “The possibility of having a different action or a terror attack, is higher than the possibility of having a technical failure.”

On the other hand, French foreign minister Jean-Marc Ayrault this morning still refused to draw conclusions about the cause of the crash.

“We’re looking at all possibilities, but none is being favoured over the others because we have absolutely no indication on the causes (of the crash),” Jean-Marc Ayrault told French television, according to AFP.

France had the highest number of nationals on board, following Egypt, with 15 French passengers.

However, the US has reviewed satellite imagery and found no sign of an explosion on board the missing EgyptAir flight, The Mirror reports.

But officials from several authorities, who wished to remain anonymous, said they had only made initial examinations. Nevertheless, they added the United States had not ruled any theories including mechanical failure, terrorism or a deliberate act by the pilot or crew.

Former head of flight operations for the British Civil Aviation Authority, Mike Vivian, who is a leading aviation expert, has also raised concerns that the EgyptAir plane could have been downed by a member of staff following an inside job. His comments, which were made Good Morning Britain come as officials in France focus on whether a possible breach of security happened at Paris’ Charles de Gaulle airport.