European airports reopen

Flights in and out of European airports returned to nearnormal on Monday after another weekend disruption due to drifting ash from an Icelandic volcano.

However, transatlantic flights may have to be rerouted northward over Greenland to avoid an ash cloud in the mid-Atlantic and could face delays.

Eurocontrol, the European air navigation agency, said all the Continent's airports were operating normally on Monday. The agency expected about 28,500 flights within the European area, which is about 500 below average for a Monday at this time of year.

"Areas of high ash concentration have dispersed overnight over continental Europe," the agency said.

"There is an area of ash cloud in the middle of the North Atlantic which is impacting transatlantic flights. While most of these flights are operating, many are having to make significant reroutings to avoid the area of ash cloud coverage, resulting in delays."

Up to 20 Spanish airports, including Barcelona, had to close over the weekend, while Lisbon airport had to shut down on Sunday. There were 23,491 flights within Eurocontrol's area on Sunday, which was about 1,500 below the normal traffic level.

Eurocontrol said Monday afternoon forecasts suggest the higher ash concentration could move in a northeasterly direction from the Atlantic into the Iberian Peninsula.

Inmid-April, the ash forced airlines to ground more than 100,000 flights and left as many as 10 million passengers stranded for days.

Volcanic ash can clog jet engines, causing them to stall.

Gritty ash has been spewing from a volcano in Iceland's Eyjafjallajokull glacier since April 13, following its first eruption in late March. Disruption of air travel occurs when wind currents blow the airborne ash into international flight lanes at altitudes where passenger aircraft fly.