Thailand on Tuesday confirmed its first two cases of swine flu in people who had travelled to Mexico, becoming the only Southeast Asian nation hit by the virus so far.
Public Health Minister Witthaya Keawparadai said the patients, both Thai nationals, had recovered and there were no signs that the A(H1N1) virus had spread.
"There are two confirmed cases of A(H1N1), both of them contracted from Mexico," Witthaya told a press conference in Bangkok.
The cases came to light after the patients returned separately from visits to Mexico, the epicentre of the outbreak, suffering from mild fever, but recovered after treatment with anti-viral drugs, Witthaya said.
The Centers for Disease Control and Prevention in the United States confirmed the virus in a sample from the first patient, while a Thai laboratory confirmed the second case, he added.
Medical authorities were keeping three people who had been in contact with the first person and five people in contact with the second patient under surveillance, he added.
None had reported signs of infection, he said.
The ministry later issued a statement urging travellers returning from any foreign destination to see a doctor within seven days if they had flu-like symptoms.
Witthaya reiterated that Thailand still has a travel warning for the United States, Mexico, Canada, Britain and Spain -- the five countries with the most number of swine flu cases.
"We have advised Thais to postpone trips to those countries and also travellers who returned from them must immediately see the doctor," he said.
The cases came just days after Thailand hosted a major conference on swine flu, at which Asian nations agreed to increase their stockpiles of anti-viral medicines.
Health ministers from China, Japan, South Korea and the 10-member Association of Southeast Asian Nations (ASEAN) also urged global health chiefs to ensure fair distribution of medicine in case of a pandemic.
Thailand has previously been hit by avian influenza, with 25 human cases and 17 deaths since 2004. The last case here was in 2006.
Experts have warned that preventing swine flu from infecting patients who are sick with avian flu should be a top priority, especially in Asia, to prevent the viruses mixing and mutating into a highly pathogenic form.
The World Health Organization's death toll from the A(H1N1) virus passed 50 at the weekend. It has reported 4,694 cases worldwide, most of them involving relatively mild symptoms.