A South Korean man working at a North Korean industrial park has been confirmed to have contracted the influenza A (H1N1) virus, the first such infection to be detected north of the border, Seoul officials said Monday.

The worker, only identified by his family name Seo, was diagnosed with the H1N1 virus, according to Yonhap News Agency.

Seo's case raised concerns of possible infection of North Korean workers at the joint industrial park in the North's border town of Gaeseong. About 40,000 North Koreans work there for about 110 South Korean businesses.