Former Khmer Rouge head of state Khieu Samphan has been charged with genocide, a spokesman for Cambodia’s UN-backed war crimes court said Friday.

Lars Olsen said Khieu Samphan had been notified of the charge in a meeting with investigating judges Friday morning.

The tribunal announced earlier this week that Khmer Rouge Brother No 2 Nuon Chea and foreign minister Ieng Sary had been charged with genocide, marking the first time the charge had been brought against regime leaders by an internationally sanctioned court.

As with Nuon Chea and Ieng Sary, the genocide charge against Khieu Samphan stems from the regime’s treatment of Vietnamese and the Cham Muslim minority group, Olsen said.

All three men, who had previously been charged with war crimes and crimes against humanity, were also informed this week that they are now facing charges of homicide, torture and religious persecution under the 1956 Cambodian penal code, which was in effect during the regime.

Prosecutors in September requested that judges clarify the charges against the five regime leaders being held at the tribunal, including Tuol Sleng prison chief Kaing Guek Eav, alias Duch, whose trial ended in November. Olsen said Friday that a meeting with former minister of social action Ieng Thirith was scheduled for next week.

No decision has been made on whether to indict the four leaders awaiting trial, let alone on what charges they might face. Judges are expected to conclude their investigation for the tribunal’s second case in the next few weeks.

Between 100,000 and 400,000 Cham Muslims died during the regime, according to figures provided by Documentation Centre of Cambodia Director Youk Chhang, who added that it is unclear how many Vietnamese were killed.