The South Korean police on Wednesday conducted a search and seizure on the NGO Corea Alliance over suspected violations of the National Security Law.

The police searched the office of the organization, which favors the autonomous reunification of the peninsula, over accusations that it was aiding “enemy activities.”

The organization has criticized the U.S. military in South Korea for shipping anthrax bacteria into the country, opposed the deployment of the THAAD missile defense system and called for the U.S. forces’ withdrawal. It has cited national division and the occupation of a foreign power as leading to the retreat of democracy