Disruption of air traffic due to the spread of volcanic ash from Iceland worsened today and only 4,000 flights were expected in European airspace against 24,000 normally, Eurocontrol said.
The European aviation control agency reported the figures, which compared with 4,886 flights yesterday. It said 63,000 flights had been cancelled in European airspace since Thursday.
Air traffic control services were not being provided in most European airspace, but flights were taking place in southern Europe, including parts of Spain and Portugal, the southern Balkans, southern Italy, Bulgaria, Greece and Turkey, it said.
"Unfortunately the situation has deteriorated somewhat more today," Brian Flynn, deputy head of operations at Eurocontrol, said.
"The geographical area that is at potential risk from the volcanic ash cloud has slightly extended to extend further south down through to parts of France, Italy and even further south east," he said.
Asked about criticisms by German airlines that aviation authorities were not taking more account of test flights carried out to assess the safety of flying through the ash cloud, he said it was a decision for national aviation authorities.
"I can understand the frustration of the personnel of Lufthansa as everybody else who is affected by this...the information that is coming from the test flights is being analysed by all persons concerned.
"But the guidelines that are being followed by all the aviation community are that the safe operation of civilian aircraft can only take place where there is absolutely no risk of potential ash cloud," he said.
"The models that are being used by everybody at the moment show that currently there is a potential risk. And for that reason the airport closures have been made."
"As soon as we are able to, with confidence, and when I say we, I mean the entire community of aviation experts, aviation authorities, are able to declare parts of the air space and airports open, that will be done," he said.
"It is decision of each state we are in the process of coordinating everybody in the community together.
The Germans, as the others, doing their utmost to determine there is no risk to the passenger and that has to be their prime concern."
German air traffic controllers said six airports in five German cities had been opened for flights heading in an easterly direction and for planes coming from there until 6pm as a gap had appeared in the ash cloud.
Reuters