Update: June 1, 2016 at 12:45 p.m.
The crew of the French Navy's Laplace hydrographic survey ship said on Wednesday they had picked up signals emanating from one of EgyptAir Flight 804's black boxes, more or less confirming the flight went down over the Mediterranean Sea, the Associated Press reported.
"The French air accident investigation agency BEA said it's impossible to determine from the signals whether it is the flight's data or voice recorder," the AP wrote.
According to CNN, investigators have yet to retrieve more than fragmentary pieces of the plane, in addition to human remains and debris including passenger luggage.
Original story below:
EgyptAir Flight 804, en route from Paris to Cairo, disappeared from all radar and radio contact around 2:45 a.m. local time Thursday morning with 66 people on board.
Hours later, in a statement from Paris, French President François Hollande confirmed the plane had crashed, likely somewhere over the Mediterranean Sea. Depsite some speculation that an explosion aboard the aircraft had downed the plane, investigators from the United States said there was so sign that an explosion occurred, according to Reuters.
"The information that we have managed to gather confirm alas that this plane has crashed," Hollande said earlier Thursday, according to the Guardian. "Alongside the Egyptian authorities we are making sure that all the families should be informed during this test. Our thoughts and solidarity and compassion are with them."
Wreckage of the aircraft was found near Greece's Karpathos Island, Egyptian officials confirmed Thursday on Facebook.
It remains unclear what brought down the aircraft; but Egyptian authorities conceded that terrorism was more probable than technical failure.
"If you analysis the situation properly the possibility of having a terror attack is higher than the possibility of having a technical [problem]," Sherif Fathy, Egypt's Minister for Civil Aviation said during a press conference, the Guardian reported.
A preliminary U.S. assessment said that it appeared a bomb was responsible for the crash, CNN reported Thursday morning.
Rescue teams began the grim task of searching for the remains of the plane, which carried 56 passengers, three members of a security detail, two cockpit crew and five cabin crew, in the hours after its disappearance. According to the Guardian, the captain of the flight had "6,000-plus flying hours, including 2,000 on an [Airbus] A320," the variety of plane involved.
Early reports indicate that some remains, possibly including a lifejacket, have been found 230 miles southeast of island of Crete.
There were no Americans on board the flight; according to a Guardian count, the passengers included, "30 Egyptians, 15 French, two Iraqis, and one each from the U.K., Belgium, Kuwait, Saudi Arabia, Sudan, Chad, Portugal, Algeria and Canada."
According to the Guardian, there have been four Airbus A320 accidents since 2009, causing 312 deaths and 23 injuries. An Airbus A321 exploded over the Sinai Peninsula on Oct. 31 killing 224 people, with the Islamic State group taking credit. According to the Times, a local Egyptian investigation will be closely examined as previous inquiries into other air disasters involving the country have faced accusations of corruption and politicization.
Ehab Mohy el-Deen, head of Egypt's air navigation authority, told the New York Times "they did not radio for help or lose altitude. They just vanished." No evidence has emerged as to the cause of the malfunction, he said, but added, "this is not normal, of course."
As of Thursday morning, the website of EgyptAir had been updated with a statement reiterating that the cause of the crash remained uncertain.
"EGYPTAIR denies all misleading information published by news websites and on the social media channels regarding the reasons of the disappearance of EGYPTAIR flight MS804," they wrote. "The company confirms that the reason of disappearance hasn't been yet confirmed."
This is a developing story and will be updated.
Additional reporting by Jon Levine
Correction: May 19, 2016
An earlier version of this article misstated the position held by Ehab Mohy el-Deen. He is the head of Egypt's air navigation authority.