MOSCOW (AP) — Russian prosecutors have declared another two U.S. non-profit organizations "undesirable" under a repressive law intended to tighten the Kremlin's tight control over the political landscape.

The Prosecutor General's office said Thursday that the activities of the International Republican Institute and the Media Development Investment Fund "pose a threat to the foundations of the constitutional order and security of the state."

Earlier, five other U.S. non-profit organizations have been blacklisted under a 2015 law intended to cut potential sources of foreign funding for Russian NGOs.

Amnesty International criticized the latest move as part of authorities' efforts to turn the screw on Russian civil society. Sergei Nikitin, the director of Amnesty's branch in Russia, said the law aims to "isolate Russian civil society, intimidate human rights defenders and suffocate the free press."