|Millions of people have been affected by flight cancellations in Europe and across the world [AFP]
List of countries across Europe with flight disruptions due to the volcanic ash cloud as of 15:30 GMT on Wednesday:
Austria - Austria reopened its airspace on Monday but some flights remain cancelled.
Belgium - Flight restrictions were partially lifted from 06:00 GMT on Tuesday.
Bosnia - Airports open.
Bulgaria - All airspace and airports open.
Czech Republic - Air space reopened on Monday.
Croatia - Airspace and all airports open.
Denmark - All airspace open since 9:00 GMT Wednesday.
Estonia - Airspace reopened at 20:00 GMT on Tuesday.
Finland - Helsinki airport closed again at 12:00 GMT on Wednesday after being opened briefly.
France - All long-haul flights to and from France and three quarters of shorter services were operating as scheduled on Wednesday.
Germany - Airspace fully reopened from 9:00 GMT.
Hungary - Airspace fully open since Tuesday.
Iceland - Air space open but many flights to Europe cancelled.
Ireland - Airspace reopened.
Italy - Airspace reopened.
Latvia - Airspace reopened at 06:00 GMT on Tuesday.
Lithuania - Airspace is open.
Luxembourg - Luxembourg Airport reopened at 08:00 GMT on Tuesday.
Moldova - International flights resumed.
Montenegro - Airports open.
Netherlands - Passenger flights began on Monday. Night flights resumed on Tuesday.
Norway - Airspace open.
Poland - Airspace open since Wednesday morning.
Romania - Airspace reopened on Monday at 18:00 GMT with all airports operating.
Russia - All airports open. Aeroflot flying to the United States via the North Pole.
Serbia - Airports open.
Slovakia - Airspace open.
Slovenia - Airspace reopened at 10:00 GMT on Tuesday.
Spain - Reopened all airports on Sunday.
Sweden - All restrictions lifted on Wednesday.
Switzerland - Reopened airspace on Tuesday.
Turkey - All airports open. Planes flying out of the Black Sea cities of Samsun, Sinop and Zonguldak have been advised not to fly higher than 6,000 metres.
Ukraine - Kiev's Borispol international airport open.
United Kingdom - All UK airspace reopened at 21:00 GMT on Tuesday but airspace over the Scottish isles of Orkney and Shetland have been temporarily reclosed.