YANGON, Myanmar -- Health officials in Myanmar said that the H1N1 virus, also known as swine flu, has killed three people out of 13 confirmed cases this month.

Khin Theingi Myint, a doctor in Yangon General Hospital, said that two infected patients died after being admitted to his hospital and one died earlier this month in Chin state in western Myanmar, where 11 of the infections were found.

The Health Ministry first confirmed the batch of cases on Monday, July 24.

The infections are from the type of H1N1 virus that was first identified in Mexico in 2009, which caused an outbreak that killed several thousand people worldwide. It is usually caused by exposure to infected pigs and is now treated as seasonal flu rather than a major health threat, because it generally causes fatalities only among people with underlying health problems.

The virus also was found in Myanmar during the 2009 to 2010 outbreak.

Confirmation of the new cases has been widely discussed on social media.

Since Monday, more people than usual have been wearing surgical masks in crowded areas of Yangon, the country's capital. (AP)