© Agence France-Presse / Sigurlaug LinnetA cloud of smoke and ash is seen over the Grimsvoetn volcano on Iceland on May 21, 2011.
On Tuesday morning, the ash blew in over Norway's southwestern towns of Karmoey and Stavanger before blowing back out to sea, the country's airport operator Avinor said.
In Denmark, a small zone of airspace in the northwest over the North Sea was closed from 0600 to 1200 GMT but has no real impact on air traffic, said Jan Eliassen, a spokesman for Danish air traffic control Naviair.
"According to the last estimates, the ash is of such a density that we thought it necessary to close a small part of Danish airspace over the North Sea, but it will not affect (air) traffic," he said.
The closure was up to an altitude of 6,000 metres (nearly 20,000 feet), and Eliassen explained that most aircraft in the region fly above that altitude.
