The United States is slapping drug trafficking sanctions on leaders of a Kurdish rebel group.

The U.S. Treasury Department said that it would add five individuals tied to Kongra-Gel to a sanctions list that already covers the group more generally.

They include Cemil Bayik and Duran Kalkan, who the U.S. says founded the group, as well as Remzi Kartal, Sabri Ok and Adem Uzun. The Treasury Department alleges that Kongra-Gel maintains a drug trafficking network across Europe that helps fund the group.

Kongra-Gel, formerly Kurdistan Workers' Party or PKK, has been fighting for self-rule in the mainly Kurdish areas of southeastern Turkey since 1984. The United States considers the group a terrorist organization.