Airports across the UK have been deserted and passengers left stranded
Two church groups claim they are effectively under house arrest in a hotel after becoming stranded in India due the UK airspace closure.
Fourteen people from two Hampshire churches were due to board a connecting flight to Heathrow in Delhi on Thursday after a trip to Nepal.
They were put up in a hotel by their airline, but the authorities say this has broken their temporary visa terms.
They are refusing to go back to the airport where their passports are held.
The groups say thousands of people are stuck there and supplies are running low.
The Foreign Office said it was doing all it could to help people stranded abroad.
All UK flights have been suspended due to volcanic ash drifting over the UK from an eruption in Iceland.
Chris Kilby was on the trip with the Southampton and Winchester family churches.
He said: "They can fly us to Hong Kong, Bangkok or to Katmandu, where we have come from, or leave us at Delhi airport.
"At the moment at Delhi airport there are probably thousands of people, very few toilets, no water or food left and there is fighting breaking out apparently.
"We have children and young people on this trip with us so we are not prepared to go to Delhi airport.
"We only have transit visas so we got halfway and are now stuck in Delhi.
"We don't have permission to leave any hotels so we are basically under house arrest.
"They have taken our passports which are being stored at the airport."
He said he was negotiating with the hotel and the Jet airline about what to do next.