PHNOM PENH, Cambodia (AP) — The international tribunal to judge the criminal responsibility of former Khmer Rouge leaders for the deaths of an estimated 1.7 million Cambodians has opened its session to deliver its verdicts on charges of genocide and other crimes.

Facing judgment on Friday are Nuon Chea, 92, and Khieu Samphan, 87, the last surviving senior leaders of the radical communist group that brutally ruled Cambodia in the late 1970s. They are already serving life sentences after being convicted in a previous 2011-2014 trial of crimes against humanity connected with forced transfers and disappearances of masses of people.

The Khmer Rouge sought to achieve an agrarian utopia by emptying the cities to establish vast rural communes. Instead their radical policies led to what has been termed 'auto-genocide' through starvation, overwork and execution.