South Korean media discovered accounts thought to belong to Kim Han-sol, the 16-year-old son of Kim Jong-nam, Kim Jong-il's eldest son, on Saturday.

BBC: North Korean leader's grandson Facebook pages revealed

On Sunday ceremonial head of state Kim Yong-nam praised Kim Jong-il's role in the rocket launch at the giant rally in a Pyongyang sports stadium.

BBC: North Koreans mark Kim Jong-il death anniversary

"Respected Comrade Kim Jong-un is our party, military and country's supreme leader who inherits great comrade Kim Jong-il's ideology, leadership, character, virtues, grit and courage, " Kim Yong-nam told the massive crowd gathered in Kim Il-sung square.

BBC: North Korea hails Kim Jong-un as leader