Search teams in the Mediterranean have picked up a beacon believed to be from the EgyptAir plane which crashed, killing all 66 people on board, the chief investigator has said.
Ayman al-Moqadem said the discovery narrows down the search area to a three-mile (5km) radius.
But he insisted this does not mean the flight data and cockpit voice recorders - the so-called "black boxes" - have been found.
Mr al-Moqadem said finding the boxes requires highly sophisticated technology.
Speaking to reporters on Thursday, he said the signal that was picked up comes from one of the devices on the plane transmitting its location.
France's air accident investigation agency has said a French naval ship which specialises in underwater searches will help search for the black boxes.
Flight 804 was flying from Paris to Cairo when it disappeared from the radar.
Egyptian officials have said they believe terrorism is a more likely explanation than equipment failure, or some other catastrophic event, and some aviation experts have said the erratic flight reported by the Greek defence minister suggests a bomb blast or a struggle in the cockpit.