An EgyptAir flight carrying 66 passengers and crew on a flight from Paris to Cairo went missing on Thursday, disappearing from radar over the Mediterranean Sea, Egypt's national airline said.

Officials with the airline and the Egyptian civil aviation department told Reuters they believed the Airbus A320 probably crashed into the sea.

Aboard the flight were 30 Egyptians, 15 French nationals, one Briton and one Belgian.

Families of passengers rushed to Cairo International Airport shortly after dawn while the Egyptian and Greek military scrambled aircraft and boats to search for the plane.

"An official source at EgyptAir stated that Flight MS804, which departed Paris at 23:09 (CEST), heading to Cairo has disappeared from radar," the airline said on its official Twitter account.

Later Tweets by EgyptAir said the plane, which was travelling at an altitude of 37,000 feet (11,280 metres), disappeared in Egyptian air space at 02:30 a.m., some 280 kms (165 miles) from the Egyptian coastline, before it was due to land at 03:15 a.m.

"There was nothing unusual," EgyptAir vice chairman Ahmed Adel told Reuters. "The search and rescue aircraft from the Egyptian air force are at the position where we lost contact. They are still looking and so far there is nothing found."

NO DISTRESS CALL

Egyptian state newspaper Ahram reported no distress call was made and the last contact was 10 minutes before the plane disappeared.

The aircraft was carrying 56 passengers, including one child and two infants, and 10 crew, EgyptAir said. Earlier it said 59 passengers were aboard but then revised the figure.

The pilot had clocked up 6,275 hours of flying experience, including 2,101 hours on the A320, while the first officer had 2,766 hours, the airline said.

Greece said it had deployed aircraft and a frigate to the area to help with the search.

A Greek defence ministry source said authorities were also investigating an account from the captain of a merchant ship who reported a 'flame in the sky' some 130 nautical miles south of the island of Karpathos.

The weather was clear at the time the plane disappeared, according to weather reports.

Speed and altitude data from aviation website FlightRadar24.com indicated the plane was cruising at the time it disappeared.

TOURISM DISRUPTED

A spokesman at the French foreign ministry said it had no further information. The French aviation authority could not be reached immediately for comment.

Under U.N. aviation rules, Egypt will automatically lead an investigation into the accident assisted by countries including France, if it is confirmed that an Airbus jet was involved.

With its ancient archeological sites and Red Sea resorts, Egypt is a popular destination for Western tourists. But the industry was badly hit following the downing of a Russian jet last year, the ongoing Islamist insurgency and a string of bomb attacks in the country.

An Airbus A321 operated by Russia's Metrojet crashed in the Sinai on Oct. 31, 2015, killing all 224 people on board. Russia and Western governments have said the plane was likely brought down by a bomb, and the Islamic State militant group said it had smuggled an explosive device on board.

Reuters reported in January that an EgyptAir mechanic, whose

cousin joined Islamic State in Syria, is suspected of planting the bomb, according to sources familiar with the matter.

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.

The last fatal incident involving an EgyptAir aircraft was in May 2002, when a Boeing 737 crashed into a hill while on approach to Tunis-Carthage International Airport, killing 14 people.

In October 1999, the first officer of a Boeing 767 deliberately crashed the plane into the Atlantic Ocean about 60 miles south of Nantucket Island, Massachusetts, killing all 217 people on board.