A US navy vessel has located the flight recorders from an Ethiopian Airlines plane that crashed off the coast of Lebanon two days ago with 90 people aboard, a security official said.

'The US ship located the black boxes 1,300 metres underwater and 8 km west of Beirut airport,' the security official told Reuters, adding that search teams now had to assess the best way to retrieve the recorders.

Flight ET409, a Boeing 737-800, was carrying mostly Lebanese and Ethiopian passengers and was heading to the Ethiopian capital Addis Ababa.

The plane apparently broke up in the air before plunging in a ball of fire into the Mediterranean during a thunderstorm early on Monday.

The security official said it was still too early to say whether the USS Ramage, brought in to help with the search, had also located the plane's fuselage.

'Theoretically the black boxes should be inside the plane's fuselage, but this is all speculation at the moment,' he said.

Lebanese and international teams, including European and U.N. peacekeeping ships, helicopters, planes and divers have been scouring a search area 10 km (6 miles) out to sea and 20 km long for the plane's fuselage and more of its victims.

The search has been hampered by rough seas and because of the uneven depth of the sea bed.

The flight recorders should shed light on why the pilot did not respond to a request to change direction even though he acknowledged the control tower's commands.

Transport Minister Ghazi Aridi said the plane made a sharp turn before disappearing off the radar. He said it was too early to draw any conclusion of pilot error.

Only 14 bodies and some body parts have been recovered since and authorities have all but given up on finding survivors.

The eight-year-old plane last underwent a maintenance check on Dec. 25 and no technical problems were found.

The last fatal incident involving Ethiopian Airlines was in November 1996 when a hijacked Boeing 767 crashed off the Comoros Islands, killing 125 of the 175 passengers and crew. – Reuters