Expect more flight disruption over the next few days.
More info on the Beeb here - http://news.bbc.co.uk/1/hi/uk/8670560.stm
Most of northern Italy's airports are closed until at least midday, and France, Switzerland, and northern Portugal may also be affected.
The Met Office said ash could return to UK airspace on Sunday and next week.
Six Scottish airports will be closed until at least 1300 BST. Flights to Spain, France and Portugal were grounded on Saturday.