Europe's biggest airports are to remain closed as a cloud of volcanic ash continues to drift across the continent. 20 countries have now closed down their airspace partially or fully causing the worst distruption of international air travel since the 09/11 terrorist attacks in 2001. Germany has now extended the closure of its skies till 02 am local time on Sunday as... winds are still driving the huge cloud of ash from Iceland towards the east and the south. It now covers most northern and central regions. Aviation officials say airplane engines could become clogged up and stop working if they tried to fly through the ash. Tens of thousands of passengers remain stranded, and even in a best case scenario it would take days before operations are back to normal.