The European air-traffic agency says some 500 flights were canceled on May 24 as an ash cloud from an erupting volcano in Iceland spread over Northern Ireland, Scotland, and Scandinavia.
The ash cloud from Iceland's Grimsvotn volcano, which erupted on May 21, caused a brief disruption in Norway's air traffic and also forced a small part of Denmark's airspace to close.
It also forced U.S. President Barack Obama, who is on a European tour, to change his travel plans, arriving one day ahead of schedule in Britain.
The cloud is expected to reach the southwest of Sweden later in the day on May 24.
Earlier today, Brian Flynn, head of operations at the Brussels-based Eurocontrol, said the ash cloud was expected to move southward.
"There is some risk that further down in Europe, particularly in the western seaboard, western France down towards the Iberia peninsula could have some ash coverage later on during the course of the week," he said.
"But at this stage it would not be realistic to give any sort of firm forecast of what the impact would be."
Experts say there is little chance of a repeat of last year's six-day travel chaos caused by an ash cloud from another Icelandic volcano, which left millions of travelers stranded across Europe.
compiled from agency reports