Egypt's aviation minister said he could not rule out that an attack or a technical failure brought down an EgyptAir flight over the Mediterranean on Thursday, and no wreckage had been found.

"I don't deny the hypothesis of a terrorist attack or something technical. It is too early," Sherif Fathy told a news conference.

"I have no information that wreckage has been found for now," he said, adding that he could not even confirm whether the plane had crashed.