South Korea’s spy agency raided the home of a pro-unification Progressive Party member last week, according to the party and the country’s largest trade union, in the latest crackdown over alleged violations of the National Security Act (NSA).

The National Intelligence Service (NIS) and police conducted the search and seizure operation against Kang Eunju, the former leader of the party’s Jeju division, and six other progressive organizations on the island on Wednesday, according to Jeju’s branch of the Korean Confederation of Trade Unions. The NSA is a Cold War-era law that stipulates punishments for pro-North Korea activity.