Passengers at Glasgow Airport wait for buses to take them to other airports
Most airports in Scotland have grounded flights again because of the risks from a rise in volcanic ash levels.
The Civil Aviation Authority (CAA) said no flights would be allowed from Glasgow until 0100 BST on Thursday.
Airspace above Edinburgh airport, which closed at 1300 BST, reopened at 1900 BST.
Flights from Prestwick and Campbeltown are currently grounded. Inverness airport reopened at 1300 BST. Aberdeen airport has remained open.
No-flight restrictions were also introduced between 0700 BST and 1900 BST at Stornoway, Benbecula, Tiree, Islay and Barra in the Hebrides.
Passengers have been advised to check with airports before travelling.
Some were taken by bus from Glasgow airport to catch flights from Edinburgh and other airports.
However other passengers in Glasgow saw their holidays cancelled.
Mabel McGeachie, 62, from East Kilbride, should have been travelling to Malaga with 10 friends and relatives for her daughter's hen night.
But their flight was cancelled with the next available on Sunday, the day they were meant to return from their trip.
She said: "We are feeling disappointed as we were looking forward to it and I don't think we'll be able to rearrange it."
Others were trying to make arrangements to get to alternative airports.
Sarah Wright, 22, a nurse from Edinburgh, was supposed to be travelling from Glasgow to Vancouver in Canada to go on a six-week trip with a friend.
They are being taken by bus to Manchester to catch an alternative flight.
She said: "We booked the trip a year ago. I just hope we get there."
Myra Grainger, 67, was flying to New York to get back to work but her flight with Continental was cancelled.
Passengers have been advised to check with airports before travelling
She was told there was room on a flight from London later and was trying to arrange to get there by train or plane.
She said: "I just hope I don't get lost. I've got to go to work."
Meanwhile, Ross County FC were forced to abandon their trip to a training camp in Spain ahead of the Scottish Cup final against Dundee United on 15 May.
The squad of 20 players and coaching staff were due to travel from Glasgow airport to Marbella on an easyJet flight but it was cancelled.
They were only an hour into their journey south from their base at Dingwall, Ross-shire, when they heard of the cancellation and returned home.
The Scottish government has reactivated the emergency response committee which was established in the wake of the flight chaos caused by the Eyjafjallajokull ash cloud last month, which left thousands of Scots stranded abroad.
Speaking following a meeting of the committee, Transport Minister Stewart Stevenson said current forecasts indicated normal air services should resume on Thursday.
But he added: "This volcano is unpredictable and the threat of further volcanic ash cover in the coming weeks remains."
He said the committee would continue to monitor the situation closely, with a further meeting scheduled for Thursday.
First Minister Alex Salmond has criticised the CAA over its advice about flights.
The organisation had warned on Tuesday night that all airspace in Scotland would be closed but by Wednesday it said some airports could open.
Mr Salmond said the CAA had apologised for giving "unclear information" which had caused some airlines to cancel flights unnecessarily.
He said he would be emphasising to the CAA the importance of giving exact and precise information in future during what he called a "very serious situation".
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