Air passengers are facing further misery as the Icelandic volcanic ash cloud returned.
The skies over parts of Scotland have been closed tonight as a precaution after an increased concentration of volcanic ash was detected in the atmosphere, the Civil Aviation Authority (CAA) said.
The ash is forecast to exceed the safe level agreed by the CAA and airlines in the Outer Hebrides tomorrow.
Airspace over the Outer Hebrides was closed to all operations at 6pm following advice from the Met Office.
The closures could see flights to and from the Western Isles cancelled but the situation will be constantly reviewed.
Passengers are advised to check with their airline before travelling.
A CAA spokesman said: "From 6pm today airspace over the Outer Hebrides will be closed to all operations following Met Office advice that concentrations of ash in the atmosphere are expected to exceed the safe levels agreed by manufacturers.
"The closures will mean operations from Barra and Benbecula will cease until airspace reopens."
The move follows suggestions from the Irish Aviation Authority (IAA) for a no-fly zone to be imposed over Ireland tomorrow after the Volcanic Ash Advice Centre (VAAC) said a plume of ash is threatening to drift across the country.
It is believed the ash cloud, currently heading towards Donegal in the north west of the country, could move across the country with north-easterly winds.
IAA's chief executive Eamon Brennan: "At the moment we have a slither of denser ash over the midlands and if this continues for the next number of hours we have no option, based on the new regime imposed in Europe last week, except to impose a no-fly zone and a 60-mile buffer zone which would effectively close Shannon and Dublin airports."
Last month tens of thousands of Britons were stranded abroad and faced long delays when airspace was closed by the eruption of Iceland's Eyjafjallajokull volcano.