RIO DE JANEIRO - Brazil was Thursday recovering debris from an Air France jetliner that came down in the Atlantic, as conflicting clues emerged as to the cause of the disaster.
Brazilian families of the some of the 228 people on board the flight also attended a religious memorial service in Rio de Janeiro, along with the French and Brazilian foreign ministers.
Brazilian navy vessels had turned their attention to plucking the debris from the ocean after a fruitless search for bodies from Air France flight AF 447, which came down 1,000 kilometers (600 miles) off Brazil early Monday as it was flying from Rio to Paris.
The first items recovered were a pallet from the cargo area of the Airbus A330 and two buoys, officials said.
They were taken by helicopter to a frigate and were later to be flown to Brazil's Atlantic archipelago of Fernando de Noronha. An air force plane would then fly them on to Brazil's northeastern coastal city of Recife for closer inspection by French investigators.
An air force spokesman, Brigadier Ramon Borges Cardoso, told reporters in Recife the debris recovered would transported to France, which is in charge of the probe into the disaster.
The reason for the accident remained unknown.
No mayday call was received, and the last communication was a series of data messages reports signaling the Airbus A330 had lost power and navigation systems before diving or breaking up.
Brazilian Defense Minister Nelson Jobim said a mid-air explosion or fire was "improbable" because the plane's jet fuel, found floating at the crash site, had not ignited.
But a Spanish airline pilot saw an "intense flash of white light" as he was flying 2,000 kilometers away from the Air France flight, his airline, Air Comet, told AFP.
His co-pilot and a passenger also saw the flash, according to the information, first given to Spain's El Mundo newspaper.
"Suddenly, we saw in the distance a strong and intense flash of white light, which followed a descending and vertical trajectory and which broke up in six seconds," the unidentified captain wrote.
Meanwhile, a report in France citing a "source close to the crash inquiry" suggested the Air France pilots might have been flying at the "wrong speed" to deal with the fierce thunderstorm that they flew into.
The newspaper Le Monde said on its website plane maker Airbus was preparing to send a warning to the operators of the hundreds of A330 jets in the world with new advice on flying in storms.
Airbus refused to comment on the report. But a company official said operational warnings to airlines using the same type of aircraft involved in an accident was standard.
But a retired pilot, Jean Serrat, told AFP that if France's BEA aviation safety agency in charge of the Air France crash investigation was authorizing such a recommendation, "it's because they know very well what happened."
"If the BEA is reminding pilots not to slow down too much, does that mean that the Rio-Paris slowed down too much?" he wondered.
Definitive answers may lie in the plane's black box data and cockpit voice recorders. But they are likely resting on the rugged sea bottom, at least 3,000 meters below Atlantic waters.
It would be extremely difficult -- maybe impossible -- to recover them, experts said.