Washington-based NKNews.org reported KCNA had deleted 35,000 articles from before October, and 20,000 articles on the website of the official newspaper of the Workers’ Party, Rodong Sinmun.

The articles taken down from KCNA included ‘‘major events’’ about the country’s recent history including the announcement of the death in 2011 of Kim Jong-il, the father of the leader Kim Jong-un.

The move comes as the nuclear-armed state makes a concerted effort to rally its people behind Mr Kim following the abrupt execution last week of his uncle, Jang Song-thaek, for disloyalty to the regime.

North Korean troops rallied in Pyongyang on Monday, pledging to ‘‘become human bullets and bombs’’ protecting Mr Kim, the official Korean Central News Agency reported.

On the same day, thousands of North Korean propaganda leaflets fell on a front-line South Korean island, warning of an attack on soldiers stationed there. A South Korean marine unit based on Baengnyeong Island in the Yellow Sea had collected the leaflets, which were carried across the border, Yonhap news agency said.

Frank Feinstein, a New Zealand-based analyst who tracks North Korean news for NKNews.org, estimated 98 per cent of articles on the KCNA website had been taken down.

"This is calculated,’’ said Mr Feinstein. ‘‘It means the order most likely came from above the individual agencies. That is why it is so interesting, it is not just an internal KCNA purge.’’

The shake-up in North Korea has set off fears of a return to the regional instability that occurred after the younger Kim assumed power following his father’s death.

With Bloomberg, AFP