SEOUL, SOUTH KOREA (AFP) - North Korean health officials have detected a swine flu outbreak in a northwestern city bordering China, an aid group said Thursday.

The infection was found in Sinuiju, prompting authorities to take emergency countermeasures, Good Friends, a Seoul-based aid group which operates in the North, said in a newsletter.

The number of North Korean children infected with A(H1N1) flu has been increasing because the anti-viral drug Tamiflu is rare in the communist country, the group said.

Pyongyang has not officially reported any cases of swine flu in the country, citing an all-out campaign to prevent outbreaks.