No group has claimed to have brought down Flight 804 after it crashed as it approached Egypt’s northern coast on May 19.

Traces of explosives have been found on some of the victims of an EgyptAir flight from Paris that crashed in the Mediterranean Sea, Egypt’s Civil Aviation Ministry said Thursday.

Flight MS 804 plunged into one of the deepest parts of the Mediterranean Sea on May 19, killing all 66 people on board.

Egypt’s investigation committee issued a statement saying the coroner had found traces of explosives on the remains of some victims. It gave no more details but said its findings were sent to prosecutors investigating foul play.

“The technical investigation committee … places itself and its expertise at the disposal of prosecutors,” it said.

Crashed EgyptAir MS804 wreckage finally found

No one has claimed to have brought down Flight 804. The Airbus A320 crashed as it approached Egypt’s northern coast before dawn.

An Egyptian source familiar with the matter said Egypt had informed France months ago about its findings, but French investigators had requested more time to study them.

“That is why it took so long to make an announcement,” the source told Reuters news agency, declining to be named as the investigation is continuing.

France’s accident investigation agency has said that smoke detectors went off during Flight 804’s final moments. Spokesman Sebastien Barthe told The Associated Press news agency earlier this year that such messages “generally mean the start of a fire”.

Industry publication Aviation Herald has reported that sensors detected smoke in the plane’s lavatory, as well as a fault in two of the plane’s cockpit windows in the final moments of the flight.

France opened a criminal investigation into the disaster in June.

EgyptAir MS804: Pilots tried to put out a fire

The crash of Flight 804 came just seven months after a Russian passenger plane was blown up over the Sinai Peninsula in an attack claimed by the Islamic State of Iraq and the Levant group.

That attack, which killed all 226 people on board in October 2015, led to widespread flight cancellations and dealt a major blow to Egypt’s vital tourism sector, already weakened by years of unrest unleashed by the 2011 uprising that toppled Hosni Mubarak.

Egypt has never officially said what caused the downing of the Russian plane. But a local ISIL affiliate said it blew up the plane with a bomb smuggled on board, and Russia said the aircraft was probably downed by explosives.

ISIL has carried out several attacks in recent years, mainly in the Sinai, where it is based, but also on the Egyptian mainland.

In recent months Egypt has spent millions of dollars trying to restore international confidence in its airport security measures.

Russia had suspended all flights to Egypt after the October crash, while Britain cancelled flights to Sharm El-Sheikh, the Red Sea resort from which the airliner took off.