A flu virus on one of the world's remotest islands yesterday prompted an international appeal for medical assistance.

Some of the 271 British citizens living on the volcanic island of Tristan da Cunha, in the south Atlantic, many of whom are asthmatic, have developed severe breathing problems.

All the residents live in Edinburgh, a settlement named after the Scottish capital in 1867 when Prince Alfred, Duke of Edinburgh, visited the island.

There is particular concern about the shortage of asthma drugs and a global operation is being co-ordinated by the Foreign Office to send medical supplies.

The department said the situation was not an "emergency" as the community had not run out of drugs.

However, there is no scheduled delivery by ship expected for many weeks, and the Foreign Office was unable to put a timetable on when any further supplies will be made available yesterday.

A spokeswoman said: "We are trying to arrange a contingency plan to get more drugs delivered to the island ahead of when they are supposed to be delivered. We are still in the planning stages.

"We really don't know how many are affected because there are quite a high number of people who have asthma."