Germany is closing its northern airspace on Wednesday because of ash from an erupting volcano in Iceland, officials say.
Bremen airport was closing at 0300 GMT and Hamburg at 0400 GMT, Germany's weather service said.
The airspace over Berlin and Hanover could also be affected.
Air traffic in Norway and Denmark has been disrupted but flights were expected to resume across the UK after some airspace in the north was closed.
Services in and out of Scotland, Northern Ireland and northern England had been badly hit, with about 500 flights cancelled across Europe.
Experts say particles in the ash could cause jet engines to stall.
http://www.bbc.co.uk/news/world-europe-13535054
Note: Update Record, 25 May 2011 Last updated at 06:59 GMT