PHNOM PENH, Cambodia (AP) — The first trial on charges of genocide against Cambodia’s brutal 1970s Khmer Rouge regime opened Friday with a prosecutor saying it will show that Cambodians were enslaved in inhumane conditions that led to the deaths of 1.7 million people from starvation, disease and execution.

Khieu Samphan, the regime’s head of state, and Nuon Chea, right-hand man to the communist group’s late leader, Pol Pot, already received life sentences in August after being found guilty of crimes against humanity, relating mostly to the group’s forced movement of millions to the countryside when it took power in 1975. They have appealed their convictions.