Ash from an Icelandic volcano is again closing airports in Western Europe.
The area affected is expected to extend south to Portugal and as far east as Barcelona in Spain and Marseille in France.
The European air traffic agency Eurocontrol says airports are closed or expected to close in northern Portugal, northern Spain and parts of southern France, affecting more than 5000 flights.
Flights are being rerouted north and south of the 2,000km cloud.
Eurocontrol officials say most flights between Europe and North America are being diverted because of the ash cloud's latest drifting.
Reuters reports an average 600 airliners make the Atlantic crossing every day.
Last month, thousands of travellers were stranded after ash shut down airspace across Europe.
Recent images have shown activity in the Eyjafjallajokull volcano intensifying.
