SEOUL, Aug. 15 (Xinhua) -- South Korea reported the first death case from influenza A/H1N1 on Saturday amid growing concerns, the nation's health authorities announced amid the Seoul government's stepped-up efforts to tackle the global pandemic.

    The late patient, whose identity is yet to be disclosed, is reportedly a man in his 50s who has recently visited Thailand, according to the Ministry of Health, Welfare and Family Affairs.

    Showing flu-like symptoms after returning home on Aug. 8, he was admitted to a local hospital, health authorities said.

    Although the exact reason for his death is still under investigation, pneumonia, caused by the A/H1N1 influenza virus, is presumed to be the culprit, authorities added.

    "We were notified by hospital officials that he died of pneumonia and other resulting complications earlier in the morning and an investigation is still underway to confirm the exact reason for his death," Lee Jong-koo, head of the KCDC told reporters at an emergency press briefing.

    "Tests have been conducted on 65 coworkers who traveled with the man to Thailand, as well as his family members, but no flu cases have been confirmed yet. Antibiotics are also being administered to medical staff who might have been in contact with the patient," he added.

    Amid the toll of the A/H1N1 flu infection reaching 2,032, most patients have been showing only mild symptoms, making fast recoveries after being treated with antibiotics.

    Although South Korea has been regarded as being relatively safe from the virus, the death report is adding to concerns that the need for efforts to brace for the fast-spreading virus, local Yonhap News Agency said.

    The South Korean government has recently upgraded the disease alert level to the second highest to fight for the new flu.

Special Report:  World Tackles A/H1N1 Flu