Most flights in the UK will remain grounded until early Saturday as ash from a volcano in Iceland continues to drift across Europe.
Germany and Poland closed most of their airports early on Friday and the no-flight zone now extends to Austria in the south and Lithuania in the east.
BBC News website readers around the world have been explaining how the flight ban is affecting them.
NEIL MARTINSON, DELHI, INDIA
We're stuck in Delhi at the moment. We shouldn't even be here except we had to finish our trek to Everest early as I got acute altitude sickness and had to be evacuated by helicopter to a hospital in Kathmandu.
We agreed with our insurance company to return early and got as far as Delhi when the volcano ash hit our plans.
As we were travelling to London, we didn't have visas for India. Fortunately, our airline Jet Airways, got permission for us to leave the airport and go to a hotel, where we are now.
However, we had to leave our passports at the airport, as we don't have visas, and are not allowed to leave the hotel.
Bizarrely, we were told by Jet Airways to leave our rooms at 0300 on Saturday to go to the airport, even though we know that the airspace will not be open by then.
I spoke to a Jet Airways representative who said it was to fly us back to Kathmandu.
When I said that we couldn't go back to Kathmandu he said it was because we had to go back into transit. Unfortunately, no one at the hotel is clear who is in charge of the situation.
So at this moment we know that no planes can fly but we don't know if we will be moved back to the airport.
I called the British Embassy who simply say there's nothing they can do as the Indian authorities are not issuing temporary visas - you have to have a visa to leave the airport - and it's down to the airline.
LOUISE GUINDA, ABERDEEN, SCOTLAND
I was due to fly to China on Thursday for business but instead I spent the whole morning on hold with Air France trying to change the ticket.
When I was eventually able to change it, all the flights were full until next Wednesday.
I had hotels and internal flights booked in China and childcare arranged for my son so the volcanic ash has turned into quite a financial disaster for my business.
I was due to sign off some new baby samples for my company and this delay means I have to keep the retailers waiting which isn't good for business.
Other small business owners speak about the disruption
PAUL DOUGAN, OSAKA, JAPAN
My wife and I were due to fly back to London from Osaka with Air France, changing at Paris.
The check-in staff could only offer us a delayed flight to a closed Charles De Gaulle airport, no onward journey to London and no hotel in Paris until a flight was available.
I was also concerned that flying through the dust-cloud into a closed airport could be dangerous. My safety concerns fell on deaf ears and a company line was repeated.
I was given a piece of paper headed 'contact us' with a phone number for a closed call centre. There were quite a few people in a similar situation to us and most, after long, exasperating discussions with staff, left the desk without checking in.
I think Air France should have cancelled the flight. Thankfully, my wife and I had no immediate plans in the UK so we have decided to stay in Osaka for another week.
KERRY STOTHART, BELGIUM
We are a party of 10 people including four children, one diabetic, one with ADHD and Asperger's Syndrome, and a blind lady.
This is an absolute nightmare. We were delayed leaving Atlanta last night as they were already aware of the volcano and then two hours before landing we were told we were going to Brussels.
When we landed, we were told by Delta that there were only three hotels available with only 90 rooms remaining - then we found all these rooms had gone and that we'd have to make our own arrangements at our own expense.
Four of our suitcases were damaged so badly that they have lost wheels, and we are having difficulty moving them around.
We should have been kept in Atlanta where room rates were $49 (£31), not dumped at our own expense of over 100 euros (£88) a night. My nan is in respite care and is due to be picked up tomorrow, my dad is self-employed and has lost hundreds of pounds.
We've had to pay £1400 for a coach and ferry to take us back home. And that's not until 2100 Friday.
STEVE THOMPSON, JAPAN
My wife and I are stuck in Tokyo, at the end of our trip, but we have now heard from Finnair with a firm commitment to fly us home on Monday so we are now quite pleased with them!
We feel we are among the lucky ones - we pity those without constant internet access because we could not have achieved this result without it.
Luckily, my credit card limit will stand a few extra days here but we have no clean clothes and we are both due back at work on Monday - that's not going to happen!
On the bright side we got a really good deal on the hotel and we get to see our son, who is at university here, a couple more times and fill in a few gaps in our Tokyo sightseeing. We feel really sorry for those stuck in the UK waiting to go on holiday - at least we had ours already and will soon be going home to Pudsey, in Leeds.
CODY ANDERSON, KUWAIT
We have been performing for the troops in Iraq and were due to fly out of Kuwait tonight, but we're all stranded on a US base until further notice.
I'm the sound engineer for a rock band called Catchpenny. We're all very anxious to go home.
This is going to be costly for my business as I am self-employed and need to find replacements for my shows back home in Minneapolis.
This is our eighth tour in Iraq, we've played over 100 bases. It really is very rewarding - it isn't about the money, it's about performing for the people. Everyone here is always very grateful that we come. But now we want to get back!
THEODORA KAFKIA, KUOPIO, FINLAND
I am in Kuopio, northern Finland for my PhD meeting with the professor. I was due to fly today, Friday, to Helsinki, then to Prague and finally get home to Thessaloniki, Greece, early Saturday morning.
I've now had to book a train to Helsinki and book three nights in a hotel there, until a new flight I've booked for Monday. My visa card is getting stretched!
Only Business Class was available and it's 200 euros (£175) more expensive than my original flight.
Finnair isn't answering the phones - the company's security personnel is on strike at the moment - and there's no mention of a refund on their web page.
It's very cold here, so you can't wait at the train station or airport. I just hope the flights are back on on Monday.
MATTHEW EMERY, ISTANBUL, TURKEY
I flew out to Istanbul for a few days' holiday and needed to be back for work on Saturday.
But I was emailed late on Thursday night by BA to say my flight had been cancelled - with no indication as to when I'd be able to get another.
It's not too bad - the sun is shining and I get to spend a few more days with my pal who is out here.
But work's not happy about me being stuck out here, and I don't know when I'll be able to get back now.
I'm just fortunate that I'm not staying in a hotel. Every cloud...
MORE OF YOUR COMMENTS
I am stranded at Doha airport after a 14 and a half hour flight from Melbourne. We have been here for eight hours and have been told that we aren't a priority by Qatar airways and that there are 500 people getting hotel beds before us, let alone a flight to the UK. Looks like we could be here for a while.
I live many miles away from Europe but my business of supplying fresh produce to the retailers in the UK and continental Europe is virtually at a halt. No flights northbound and I can't send cargo out, so everything is going into the bin. I have also stopped the pack house shifts because of this mess.
Neville, Nairobi, Kenya
In 1989 we were flying on a brand new KLM 747 to Tokyo via Alaska when we flew into a volcanic cloud over Anchorage. All four engines stopped and we fell around 10,000 feet before the pilot got one engine working and another just before an emergency landing. Having been through that, I can see why NATS are not taking any chances.
Paul Taylor, Hersham, Surrey
Came to Barcelona to watch Barca play on Wednesday night as a treat for my son's 10th birthday, and we're still stuck! Have just booked first available train from Barcelona to Paris on Monday night and then booking Eurostar from Paris to London. All hire cars sold out, buses full, trains full and doesn't help with the French having an intermittent rail strike so French travel is at your own risk! Just want to get home now!
George and Anthony, London
I am stranded in Florida. I am on holiday but I work for the airlines and am on a stand-by ticket. That means that I will have no chance of getting home until everyone else has been rebooked and repatriated. I was due to return tomorrow and it could be another week before I can get back, presuming the flights restart tomorrow. My son is with me and due back at school on Monday.
James F, Crawley
My boyfriend and I were supposed to be flying to Brisbane via Singapore this evening, for a trip we've been saving up for and planning for months. We have a wedding to get to on Thursday and then interconnecting flights in Australia as we're travelling around the East Coast for two weeks before heading to Japan for a week. We're both so disappointed but this is out of everyone's control, so it's just a case of waiting for further news. We're now trying to think of things to do in London to cheer ourselves up and pray we get on a flight over the weekend to make the wedding.