SEOUL, South Korea (AP) — A South Korean court sentenced a left-wing lawmaker to 12 years in prison and six colleagues to shorter terms Monday for plotting a pro-North Korea rebellion in the event of a war on the Korean Peninsula.

Lee Seok-ki from the small United Progressive Party was arrested in September for allegedly discussing attacks on national infrastructure with 130 colleagues during secret meetings in May. Tensions were especially high between North and South Korea following Pyongyang’s third nuclear test last February and its repeated subsequent threats of nuclear war against Seoul and Washington.