The pilot of an Ethiopian Airlines plane which crashed into the sea shortly after take-off from Beirut performed "a very fast and strange turn before disappearing from the radar", Lebanon's transportation minister said today.
All 90 people on board are feared dead.
Transportation Minister Ghazi Aridi told The Associated Press that the pilot flew in the opposite direction to that recommended by the Beirut control tower after taking off at 2.30am local time yesterday, during a night of lightning and thunderstorms.
The tower "asked him to correct his path but he did a very fast and strange turn before disappearing completely from the radar", Mr Aridi said.
It was not clear why that happened or whether it was beyond the pilot's control.
Like most other airliners, the Boeing 737 is equipped with its own onboard weather radar which the pilot may have used to avoid flying into thunderheads.
No survivors have been found more than 24 hours after the crash. Emergency workers have pulled bodies from the Mediterranean Sea and the numbers reported so far range from a dozen to more than 20.
Searchers were trying to find the plane's black box and flight data recorder, which are key to determining the cause of the crash.
The flight had been heading for the Ethiopian capital, Addis Ababa.
An aviation analyst familiar with the investigation said Beirut air traffic control was guiding the Ethiopian flight through the thunderstorms for the first two to three minutes of its flight.
The official, who asked not to be identified because of the sensitivity of the matter, said this was standard procedure by Lebanese controllers to assist airliners departing from the airport in poor weather conditions.
It is unclear exactly what happened in the last two minutes of flight, the official said.
Ethiopian Airlines said late yesterday that the pilot had more than 20 years of experience. It did not give his name or details of other aircraft he had flown. It said the recovered bodies included those of Ethiopians and Lebanese.
Rescue teams and equipment sent from the UN and countries including the United States and Cyprus were helping in the search today. Conditions were chilly but relatively clear - far better than yesterday, when rain lashed the coast.
Hours after the crash, pieces of the plane and other debris were washing ashore, including a baby sandal, passenger seats, a fire extinguisher, suitcases and bottles of medicine.
"We saw fire falling down from the sky into the sea," said Khaled Naser, a petrol station attendant who saw the plane plunge into the sea.
The Lebanese army also said the plane was on fire shortly after take-off. A defence official said some witnesses reported that the plane broke up into three pieces.
At the Government Hospital in Beirut, Red Cross workers brought in bodies covered with wool blankets as relatives gathered nearby.
Marla Pietton, wife of the French ambassador to Lebanon, was among those on board, according to the French Embassy.
Aviation safety analyst Chris Yates said reports of fire could suggest "some cataclysmic failure of one of the engines" or that a bird or debris had been sucked into the engine.
He noted that modern aircraft are built to withstand all but the foulest weather conditions.
"One wouldn't have thought that a nasty squall in and of itself would be the prime cause of an accident like this," said Mr Yates, who is based in Manchester, England.