BBC correspondents report on how the continuing eruption of a volcano in Iceland is affecting countries around the world.
LORNA GORDON, ICELAND
It is quite a complicated dynamic as to what is happening with the volcanic eruption.
We have been speaking to geophysicists and meteorologists from the Icelandic civil defence department.
The volcano is producing much less ash than it was previously
They say that it is not the current ash that is being emitted by the volcano which is causing problems over Europe.
It is the previous cloud at the beginning of this eruption - it was spewing out ash at the rate of about 500 tonnes a second up into the atmosphere.
The level of ash being produced now has dropped considerably.
Geophysicists say there are three separate craters at the moment, lava has been spotted and the cloud that is being produced is lighter and not rising to such a high level.
MARIKO OI, SINGAPORE
Queues of stranded passengers fill the departure lounge at Singapore's Changi airport.
They are desperate to go home but they still do not know when they can.
Asian airports are also desperate for new information.
Some stranded passengers have been offered free accommodation
Cancelling all those flights is costing them millions of dollars every day.
Singapore Airlines is expected to suffer the biggest loss in the region. It gets a quarter of its revenues from Europe.
Some of the stranded passengers have been offered free accommodation, but others had to pay for their own.
With hotels in Singapore enjoying record occupancy levels, finding an affordable room is becoming a challenge.
With a trickle of flights leaving for Europe, passengers here are facing another night of uncertainty.
SARAH RAINSFORD, SPAIN
The British authorities have announced that some 100 coaches are being sent to Madrid.
Madrid is to be used as a hub for passengers to move on from
They are planning on using Barajas airport here as a hub for trans-Atlantic passengers to move on to other parts of the world.
This is a difficult logistical operation - what is being discussed is the idea of having flights that should have been heading for the UK, instead being diverted here to Madrid.
It would in particular be flights from America and from Asia.
Getting people on from Madrid to their final destinations is a difficult operation.
It has taken some time to arrange but it does appear to be bearing fruit now.
We are expecting those coaches at some point - and the passengers hoping to get on those coaches are beginning to arrive at the airport.
There are families here who have made their way from Johannesburg and Tel Aviv.
Madrid is likely to become the congregation point for British people who want to get back to the UK.
For anyone else in northern Europe, there have been windows of opportunity and flights taking off to places such as Brussels, Prague and Amsterdam.
HUGH SCHOFIELD, FRANCE
Things are moving here for the first time since Thursday.
But it is still only a minority of flights that are leaving and the situation is not stable.
Twenty-four hours from now, things could be very different.
Right now the two big airports in Paris, Orly and Charles de Gaulle, are operating at about 30% capacity.
Flights are taking off from Paris to the south of France, via agreed 'corridors'
In that load of flights, 75% are long haul, which is allowing the airlines to get rid of the backlog of disgruntled and distressed passengers both here and abroad.
Tens of thousands of French people are abroad and the government has made it quite clear that they are its priority - and therefore, it hopes, the priority of the airline companies - to get those people back.
Flights are moving from Orly and Charles de Gaulle straight towards the south, down corridors which seem to have been agreed upon at a European meeting Monday.
The French government says the flights are being monitored, they are under "controlled conditions".
In other words, the situation is being constantly assessed.
For the moment, conditions seem to be good. It is hoped that this will be the beginning of a return to normality.
But I think everyone would agree that there has to be a strong element of caution and doubt in anything that predicts beyond the next 24 hours.
ROB WALKER, SPAIN
The British navy vessel HMS Albion has arrived in the northern city of Santander, to pick up more than 200 British troops who have been stranded here returning from Afghanistan.
They have made their way here from Cyprus.
Thousands of Britons are stranded in Spain and ferries are booked up
But the last thing the government wanted was for the ship to go back with any spare capacity.
Around 300 civilians, tourists stranded here, have now been loaded on to HMS Albion.
It is a difficult situation here, as the 300 who have boarded the ship are people the British Foreign Office has identified as vulnerable - people on medication and groups of children.
But there are plenty of other people who have come to Santander and other ports, trying to get back to Britain, who can not get on HMS Albion.
The commercial ferries here are full up until next Thursday.
Brittany Ferries is telling people here they have a better bet if they go to one of the northern Channel ports in France.