Special Report: Iceland volcano eruption

Successful test flights conducted by major European airliners have failed to give enough confidence to air safety agencies across Europe to fully lift their flight bans.

Passengers wait as flights restriction continues at Vienna International Airport in Vienna, Austria, April 17, 2010. [Liu Gang/Xinhua]

When Germany's Frankfurt airport was allowed to resume operating temporarily until 8:00 p.m. (1800 GMT) on Sunday, most of other European airports that were shut down due to the volcanic eruption in Iceland would remain closed for some time as the ash cloud was spreading further southward and eastward.

Britain's National Air Traffic Service (NATS) on Sunday said no flights would be allowed in or out of UK airspace until at least 0700 BST on Monday.

"Conditions around the movement of the layers of the volcanic ash cloud over the UK remain dynamic," the NATS said in a statement.

All continental French airports will remain closed until at least Monday 0600 GMT due to the spread of clouds of volcanic ash.

Austria's air traffic controllers on Sunday decided to further extend the closure of Austrian airspace until 2:00 a.m. (0000 GMT) on Monday.

Meanwhile, the whole of Denmark's airspace and that cross northern Italy will remain closed until 0600 GMT on Monday. Switzerland also extended a ban on commercial flights at its airports until Monday at 1200 GMT.