The United States on Tuesday slapped financial sanctions on Chechen leader Ramzan Kadyrov, accusing him overseeing a systematic campaign of deadly repression, the Treasury Department announced.

In addition to the head of Russia's Chechnya Republic, the U.S. Treasury said on its website that it was sanctioning four Russians under a U.S. law known as the Magnitsky Act.

The four Russian citizens were sanctioned over gross violations of human rights and include Chechen security official Ayub Kataev.