North Korea recently appointed a new head of its military intelligence agency, research by South Korea’s Ministry of Unification (MOU) revealed Wednesday, in two new books laying out a number of recent changes in the country’s top brass.

According to the research, Rim Kwang Il replaced Jang Kil Song, who has served as the chief of the Reconnaissance General Bureau (RGB) — the country’s top foreign intelligence-gathering body — since 2016.

Rim replaced Jang in December last year, the MOU said, and was promoted to full memberof the Workers’ Party of Korea (WPK) CC during a ruling Workers’ Party