Egyptian jets and naval vessels found "personal belongings of the passengers and parts of the plane debris" 180 miles (290 km) north of Alexandria, Army Spokesman Brig. Gen. Mohammed Samir said on Friday.

The military said it is searching the area for the black box of the Airbus 320 which lost contact at 2.45 a.m. local time Thursday morning.

The Egyptian presidency expressed its "deep sadness and extreme regret" over the deaths of those on board in the first official recognition of the tragic crash of the missing plane.

Passengers on board included 30 Egyptians, 15 French and one Briton, Egypt’s Civil Aviation Ministry said.

Egyptian airport officials said three French and three British investigators and an Airbus technical expert have arrived in Cairo to join the investigation into what caused the crash.

The Egyptian military says that no distress call was received from the pilot.

The country's aviation minister Sherif Fathi has said the likelihood the plane was brought down by a terror attack is "higher than the possibility of a technical failure."

France's foreign minister and a top transport official have said there is still no sign of what brought down the flight.

Foreign Minister Jean-Marc Ayrault said Friday on France-2 television there is "absolutely no indication" of the cause.