North Korean defector Hwang Jang-yeop has made his first public appearance after a recent death threat.

Hwang attended a ceremony in Seoul on Saturday celebrating the fifth anniversary of the establishment of the Association of North Korean Defectors. Hwang serves as the group's honorary chairman.

Hwang suspended all public activities after about a dozen letters containing death threats were delivered to him earlier this month. One of the letters contained a picture of Hwang that was pierced with a butcher's knife and covered with fake blood.

Police said they have yet to find out who sent the letters.

The 80-year-old Hwang, a former secretary of the North Korean Workers' Party, defected to South Korea in 1997 to become the highest ranking North Korean official ever to seek asylum in Seoul.