Rescuers are searching waters deep in the Atlantic Ocean for a French airliner which disappeared in a storm early on Monday.
The search, involving ships and planes from many nations, was part-suspended overnight, but aircraft with monitoring equipment continued to scour the sea.
Brazilian authorities are investigating reports that another passenger plane's crew saw "bright spots" in the ocean.
The Air France Airbus was heading from Brazil to Paris when it disappeared.
France believes there is little hope of finding survivors from among the 228 passengers and crew aboard the flight.
Vessels from France, Spain, Senegal and Brazil are involved in the search, while the United States is said to be offering help with satellite reconnaissance.
US President Barack Obama said Washington would provide "any help necessary" to find out what had happened to the plane.
Plane crews have narrowed their search to a zone half-way between Brazil and west Africa, said Pierre-Henry Gourgeon, chief executive of Air France, late on Monday.