Two more people in England have been confirmed with swine flu, the Health Protection Agency said.
The new cases, together with three in Scotland announced previously, take the total number of confirmed cases in the UK to 87.
The latest patients to be confirmed with the virus are both adults, one who recently returned from travelling and another whose source of infection is yet to be established.
One is from the South East and the other from the East of England region.
The latest cases come after the Foreign Office told British travellers they should feel free to go to Mexico after a fall in the number of new swine flu cases.
Holiday makers and business travellers had been advised against all non-essential travel to the country, but the Foreign Office has now changed its guidance.
A spokesman said: "This change follows a decline in new cases of swine flu reported in Mexico since a peak on April 26 and takes into account information and advice from a variety of sources, including the UK Health Protection Agency."
Tests on the virus have suggested the strain is less virulent than first feared and the World Health Organisation is not recommending any global travel restrictions.
Nonetheless, the Government has signed contracts for up to 90 million doses of a pre-pandemic swine flu vaccine.
In Mexico more than 60 people have died as a result of the H1N1 virus, with most cases reported in Mexico City. The country has confirmed more than 2,400 cases. Around the world, 34 countries have reported more than 7,500 cases of infection.
