Scientists say a volcanic ash cloud keeping most of Britain's air space closed is due to a change in the wind, not a new burst from Iceland's volcano.

Gudrun Nina Petersen of the Icelandic Meteorological Office says volcanic ash that was drifting over the North Sea is being pulled back over Britain by winds from both the northeast and northwest.

The volcano in southern Iceland is still spewing smoke and lava, but the ash plume is lower than it previously was, posing less threat to high-flying aircraft.

Airplanes across Europe are gradually taking to the skies after five days of being grounded by the drifting volcanic ash. But British officials say London airports are likely to remain closed for another day.