A robot submarine has been sent to join the hunt for an EgyptAir plane that crashed into some of the deepest waters of the Mediterranean Sea last week with 66 people on board.
Eyptian President Abdel Fattah al-Sisi said his country had sent the device to aid ships and planes that are currently scouring the sea north of Alexandria for the wreckage.
Body parts, personal belongings and debris from the Airbus 320 have already been found, but the search teams are still trying to locate the black box recorders that could shed light on the cause of the crash.
Sisi said that underwater equipment from Egypt's offshore oil industry was also being brought in to help the search.
"They have a submarine that can reach 3,000 metres under water," he said in a televised speech. "It moved today in the direction of the plane crash site because we are working hard to salvage the black boxes."
He was referring specifically to a robot submarine used to maintain offshore oil rigs. It was not clear whether the vessel would be able to help locate the black boxes, or would be used in later stages of the operation.
Air crash investigation experts say the search teams have around 30 days to listen for pings sent out once every second from beacons attached to the two black boxes. At this stage of the search they would typically use acoustic hydrophones, bringing in more advanced robots later to scan the seabed and retrieve any objects once they have been found.
The US Navy's Sixth Fleet has also said one of its patrol aircraft supporting the search had spotted more than 100 pieces of debris positively identified as having come from an aircraft.
EgyptAir flight 804 from Paris to Cairo vanished off radar screens early on Thursday as it entered Egyptian airspace over the Mediterranean. The 10 crew and 56 passengers included 30 Egyptian and 15 French nationals.
French investigators say that the plane sent a series of warnings indicating that smoke had been detected on board shortly before it disappeared.
The signals did not indicate what caused the smoke or fire, and aviation experts have not ruled out either deliberate sabotage or a technical fault, but they offered early clues as to what unfolded in the moments before the crash.
Last week’s incident is reminiscent of the disappearance of Malaysia Airlines Flight 370 in March 2014, where debris from the plane continued to wash ashore two years after the crash occurred.
In January, a Chinese ship equipped with state-of-the-art sonar joined the MH370 search in order to build a picture of the underwater landscape and detect further wreckage.