British holiday companies suspended their operations to Mexico following the outbreak of the deadly swine flu virus.
Britons were warned to avoid all but essential travel to the country as world health officials said the virus can no longer be contained.
The UK braced itself for further cases as officials issued new travel advice after the World Health Organisation (WHO) raised its alert over the outbreak to level four, signifying a "significant increase in risk of a pandemic".
Tour operator Thomson cancelled two flights due to leave the UK for the Mexican resort of Cancun. The company added that it was bringing home all Thomson and First Choice holidaymakers already in Mexico.
Meanwhile, Thomas Cook and Airtours, which have about 3,000 holidaymakers in Mexico at the moment, were also expected to suspend Mexico holidays.
The first two British cases of swine flu were confirmed on Monday and more suspected infections have also emerged. The Foreign Office said: "We are now advising against all but essential travel to Mexico." It added that British nationals "resident in or visiting Mexico may wish to consider whether they should remain in Mexico at this time".
The two confirmed patients, Iain and Dawn Askham, of Polmont, near Falkirk, had reportedly been on honeymoon in Mexico and were being treated in isolation at Monklands Hospital in Airdrie, Lanarkshire.
Health officials have said the couple were not seriously ill and were recovering well.
So far 152 people are thought to have been killed in Mexico by the virus, which is caused when the H1N1 strain associated with pigs crosses over to the human population. Outbreaks have also been confirmed in the United States, Canada and Spain.
Suspected cases from New Zealand to Israel were raising concern that the new virus was spreading rapidly. It was also confirmed that four people in the Republic of Ireland were being tested.
