A number of German airports halted flights this morning as ash from an Icelandic volcano drifted across northern Europe, with parts of Scandinavia also facing a risk of disruption.
The Grimsvotn volcano forced the cancellation of some 500 European flights yesterday, with Scotland especially hard hit. The number was predicted to rise to 700 today.
Eurocontrol, the Brussels-based agency responsible for some of the world's busiest air corridors, said the ash cloud may affect parts of Denmark, southern Norway and southwest Sweden today.
In northern Germany, Hamburg and Bremen airports cancelled takeoffs and landings this morning, and German authorities later closed airports in Berlin.
German airline Lufthansa advised passengers that tickets for cancelled flights within Germany could be exchanged for rail vouchers.
But as ash levels dissipated Bremen airport reopened, followed shortly afterwards by Hamburg. Services to and from Berlin are due to resume this afternoon.
Eurocontrol said the ash could drift to Poland, but a Polish air traffic control official said no traffic limitations were expected.
The ash has caused far fewer problems than last year, when more than 10 million people were hit by a six-day European airspace shutdown after another Icelandic volcano erupted. Airlines put their revenue loss then at €1.2 billion.
But the latest episode has exposed disarray among the people who decide on aviation safety as they try to apply new rules to avoid another mass shutdown. Budget airline Ryanair was again vocal in its criticism on Tuesday, and airline association IATA said more coordination was needed.
Ryanair said it had safely sent two planes into what authorities had deemed high ash zones over Scotland, and criticised "bureaucratic incompetence".
Dutch airline KLM said it would cancel 19 flights today to and from Britain, Norway, Sweden and Germany. It expected to operate all other flights as scheduled.
In Iceland, volcano experts had good news for airlines as they said the eruption was petering out.
President Olafur Grimsson told the BBC: "The volcano seems to be calming down. The eruption is gradually being diminished and the ash cloud is definitely smaller than it has been."
Reuters