Civil aviation officials are closing airports in northern England, Scotland and Northern Ireland Sunday in response to a drifting, dense cloud of volcanic ash encroaching on British airspace.
The National Air Traffic Service said all airports in Northern Ireland will close from 1 pm (1730 IST), along with others in northern England including Manchester and Liverpool as well as Prestwick, in Scotland. But airports in London are to remain open for the moment.
British and Irish aviation authorities could not say when or if other airports would have to close but said they expect London's airports to remain open until at least 7 pm (2330 IST), Dublin until early tomorrow and Shannon, in western Ireland, until 11 pm (2200 GMT).
Britain's Department for Transport had warned that different parts of the country's airspace including England's southeast, home to Europe's busiest airport at Heathrow could close at different times through the next few days because of the eruption of Iceland's Eyjafjallajokul volcano.
In Iceland, civil protection official Agust Gunnar Gylfason said volcanic activity had not particularly intensified, though it does fluctuate throughout the day.
"What really changes the situation is the weather pattern," he said.
Meanwhile, German air traffic control said its air traffic won't be affected by a possible return of the volcanic ash cloud before Wednesday.
In a statement issued late yesterday it said the latest weather forecast shows that the ash concentration will remain insignificant throughout Tuesday.
Air traffic controllers previously warned of the ash cloud's possible return for tomorrow, which could have led to the closure of German airports.
The German Aerospace Center and Lufthansa both announced test flights for today to measure the ash concentration.