Clouds of ash have drifted from Iceland's Eyjafjallajokull volcano
Official advice on disruption to flights caused by clouds of volcanic ash has been "confused", a Scottish airports boss has said.
Inglis Lyon, managing director of Highlands and Islands Airports Limited (HIAL), said a press release on Tuesday warned all airspace would be shut.
But he said this was later followed by advice saying some airports could open.
The UK Civil Aviation Authority (CAA) said the situation was "regrettable" but weather patterns were changeable.
Mr Lyon said passengers and airlines had cancelled flights before detailed information was issued by the regulator in the early hours of the morning.
He said there should have been a full flight from Dundee - where the airport is operated by HIAL - to London, but this had not gone ahead.
Mr Lyon told BBC Scotland: "The regulator could have handled it better.
"I was made aware of the potential closure in Scotland last night by a press release which the CAA put out that said the entire Scottish network would be closed."
But by about 0200 BST to 0300 BST, he said a detail document for airports, airlines and pilots, known as a Notam, allowed for some flights.
Mr Lyon added: "There has been a degree of confusion caused by the issuing of two documents - one was the press release which everybody reads and the other was the Notam which is the definitive document."
The CAA said it was dealing with a frequently changing situation.
A spokesman said: "It is a very dynamic situation and we are dealing with changeable weather patterns. We are having to issue advice on a very short notice basis.
"Unfortunately, the advice we had earlier in the evening had changed by the early hours of this morning.
"It is regrettable but we are up against changeable weather patterns."
Clouds of ash have drifted from Iceland's Eyjafjallajokull volcano.
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