Britain placed on swine flu alert
The UK is on health alert following a deadly outbreak of swine influenza in Mexico and the US.
The World Health Organisation has warned all nations to keep a look out for unusual flu cases.
Its director-general Margaret Chan said the outbreak constituted a "public health emergency of international concern" and had "pandemic potential".
The H1N1 strain of swine flu usually associated with pigs has spread to humans, causing symptoms including fever and fatigue.
More than 60 people have died of pneumonia in Mexico after contracting a flu-like virus and many others - including children in a New York school - have been made ill.
Health authorities were monitoring the situation as tests were carried out to assess the potential of the virus to spread.
On Saturday night, a man on a flight from Mexico City to London's Heathrow Airport was taken to a London hospital with "flu-like symptoms".
The UK Health Protection Agency said it was keeping a close eye on the situation.
An HPA spokesman said: "No cases of swine flu have been identified in the UK or anywhere in Europe. The reported events in the US and Mexico are unusual and warrant further investigation and vigilance on the part of other countries."
Britons are not currently being advised to avoid travelling to affected areas of Mexico and the US, although anyone visiting those destinations or who has recently returned should consult a doctor if they experience flu-like symptoms.
