Pyongyang has executed up to 50 people this year including around 10 party officials for watching South Korean soap operas, according to reports.
South Korea’s Yonhap News Agency, quoting intelligence sources, said such television is banned in North Korea, amid fears the influx of outside influences could pose a threat to its leader, Kim Jong-un.
South Korea’s National Intelligence Service (NIS) said as well as the executions senior military officers had been demoted for “poor artillery accuracy”, according to Yonhap.
It comes as state media in North Korea released images of Kim, appearing to confirm reports he has been ill in recent weeks.
Kim, who has only been seen once in public since early September, was shown in some of the pictures with a walking stick.
The dictator, 31, had previously only been seen once in public since early September, fuelling speculation in the West that he has been unwell.
Pyongyang has denied he is ill, but Yonhap, quoting NIS, said he had undergone surgery to remove a cyst from his ankle.
NIS said the problem was discovered in May and that foreign doctors were dispatched to Pyongyang to carry out the procedure either in September or October.
The images released showed Kim at a newly-built restaurant for soldiers, with his wife, Ri Sol Ju, and high-ranking officials.
North Korea’s state-run television station KRT, who broadcast the pictures, did not specify when or where the visit took place.
Kim re-appeared in state media on October 14, an absence of six weeks since being shown at a concert with his wife on September 3.