Iceland's most active volcano erupted on Saturday, just a year after another eruption on the island shut down European air traffic and caused travel chaos for days.
Huge clouds of smoke could be seen in the air spurting from the Grimsvotn volcano, followed by a series of small earthquakes.
A no-fly zone was immediately designated for 120 miles (220 kilometres) in all directions from the eruption.
A spokesman for Iceland's air traffic authority said the flight ban was a precautionary measure until the full extent of the problem was known.
Icelandic Met Office geologist Hjorleifur Sveinbjornsson told the Daily Mail: 'It's a big eruption, but it is unlikely to be like last year.'
He was referring to the huge Eyjafjallajökull blast that brought parts of Europe to a virtual standstill in 2010.
He said the plume from the volcano, which last exploded in 2004, had been seen on radar screens as high as nine miles up, but he said the smoke was going straight up into the air.
University of Iceland geophysicist Pall Einarsson said: 'Grimsvotn is a very powerful volcano, so we're monitoring it closely, even if the last few eruptions have been harmless.'
He said ash was also coming from the volcano, but added: 'We do not expect this to be a big one as it's coming from the same crater as the last three eruptions, which were all small.'
A team of scientists from Iceland's capital Reykjavik flew to the area on Saturday to check on the situation.
Gudjon Arngrimsson, communications director for Icelandair, said: 'We do not expect the Grimsvotn eruption to affect air traffic to and from the country in any way.'
Air control authorities halted flights last year due to fears that the dust and ash from the Eyjafjallajökull volcano would get into engines and cause accidents after the cloud was blown into European air traffic lanes.
Mr Einarsson said: 'The ash in Eyjafjallajokull was persistent or unremitting and fine-grained.
'The ash in Grimsvotn is more coarse and not as likely to cause danger as it falls to the ground faster and doesn't stay as long in the air as in the Eyjafjallajokull eruption.'
Don't fancy taking your chances in the sky? Check out our favourite secluded cottages by the sea - all in Britain:
Wonderfully secluded cottages by the sea
Another Icelandic ash cloud! But this one won't cause travel chaos
Gather your closest friends and/or family (the cottage sleeps ten) and retreat to this idyllic spot overlooking St Brides Bay, in the Pembrokeshire National Park – but make sure you get on well because there's not another soul for miles. Cliff paths lead down to the sandy beaches below and along the entire coast, making it ideal for keen walkers and twitchers. Visit bryn-y-mor-pembs.co.uk
For celebrities, hermits, recluses and lone wolves, there's no better hideaway than your own private island. Apart from the ruins of a medieval Highland fortress, the three-bed cottage is the only building on this mile-long island off the west coast of Scotland. Use of the island's motor boat is included in the rental price and can be used for exploring the nearby coves and skerries and spotting dolphins, porpoises, otters, and sea eagles. Visit torsa-island.co.uk
Not strictly speaking seaside, but we had to include this unique retreat teetering on the edge of the River Dart. Built in 1760, the completely secluded converted bathing house is only accessible by walking through fields and woodland, although a 4x4 will bring your luggage in and out when you arrive and leave. Visit helpfulholidays.com.
One of only two properties on the Kynance Downs, surrounded by National Trust land and in an area of outstanding natural beauty, Carn Goon is a corker of a beach house. All mod cons are on hand – Sky TV, Internet, a huge downstairs walk-in shower perfect for rinsing off the sand from Kynance Cove and vast tub dryers for all those beach towels – but the stunning 180 degree sea views from the wooden veranda are the true star attraction. Visit cornishcottagesonline.com
What could be more romantic than staying in an 18th century converted dovecote? These unusual looking buildings were once valuable storehouses for meat, eggs and manure, but thankfully all that has long been cleared out to make way for underfloor heating and Wi-Fi . The quirky circular rooms and stunning views along the Northumbrian Coast and over to Holy Island from the 65ft high tower remain. Visit rosscottages.co.uk
The Hebrides are not the easiest place in the British Isles to get to, but the deserted white sand beaches, turquoise seas, wildlife and whisky galore and spanking-fresh seafood (lobster, scallops and peat-smoked sea trout, mmm) more than repay the effort. Once ensconced in this traditional Hebridean thatched 'black house', watch the resident seal colony frolic outside the house and hunt for eagles and otters. Visit ownersdirect.co.uk
This one-bedroom cottage on its own private beach, with uninterrupted views across the Kilbrannan Sound to Arran and the Island of Davaar. Cosy up in front of the wood-burning stove with a dram from one of the local distilleries and croon Paul McCartney's 'Mull of Kintyre' to your loved one. If cabin fever sets in, escape three miles up the road to Campbeltown, home to the country's oldest cinema, the art deco 'Wee Picture House'. Visit kintyrecottages.com
Remember Fraggle Rock? Well, this lighthouse, at the furthest point of the Roseland Peninsula, was the setting for that well-loved Eighties children's programme. It's completely private as the lighthouse is automated these days (and the Fraggles are long gone), but bring your ear plugs if the outlook's misty as when the electronic fog signal goes off, you'll know about it. Visit ruralretreats.co.uk