Volcanic ash from Iceland wound its way south to North Africa and curled eastward, forcing authorities for the first time to shut down airports in Morocco, as well as in Spain and, briefly, in Turkey.
Ten airports in Morocco, among them Casablanca, Rabat-Sale, Tangiers, Fez, Agadir and Essaouira, almost all major tourist stops, were closed until at least 7am (0600GMT) on Wednesday.
A Transport Ministry statement carried by the official MAP news agency said it wants "to guarantee a maximum level of security for passengers" as the ash cloud passes over the kingdom on the Atlantic Coast.
Airports in Morocco, on the African continent and some 3,780 kilometres (2,350 miles) from Iceland, were not affected last month when the April 14 eruption of the Eyjafjallajokul volcano forced at least a five-day suspension of air traffic in Europe.
This time, the ash pushed south, forcing even the small airport in the Moroccan town of Tan-Tan, just north of the Western Sahara territory, to close.
The ash also was causing havoc on Tuesday in nearby Spain, forcing airports to shut down in the Canary islands of Tenerife, La Palma and La Gomera, affecting dozens of tourist flights.
On the Spanish mainland, 1,300 kilometers (800 miles) from the Canary islands, airports at Seville and Jerez in the south and Badajoz in the east were closed.
Spain also kept restrictions on planes flying between 20,000 feet and 35,000 feet (6,100 meters and 10,770 meters) above the ground, mainly affecting trans-Atlantic flights to and from other European countries.