The Khmer Rouge’s 76-year-old former head of state was rushed to a hospital with high blood pressure Wednesday as one of his ex-comrades appeared before Cambodia’s genocide tribunal.

Khieu Samphan’s condition was not considered extremely urgent “but necessitated attention” given his history of high blood pressure, tribunal spokesman Reach Sambath said. He was driven from his detention cell to a Phnom Penh hospital on his doctors’ recommendation.

The U.N.-assisted tribunal has charged Khieu Samphan with crimes against humanity and war crimes, detaining him since last November.

His hospitalization came as the tribunal was hearing an appeal against pretrial detention from Ieng Thirith, the Khmer Rouge’s former social affairs minister.

Ieng Thirith and Khieu Samphan are among five suspects facing trial for their alleged roles in the regime’s brutality. Trials are expected to begin later this year.

The tribunal is seeking justice for atrocities committed by the ultra-communist Khmer Rouge when it ruled Cambodia in 1975-79, with some 1.7 million people dying from starvation, disease, overwork and execution.

The Cambodian lawyer for the 76-year-old Ieng Thirith has said she suffers from chronic illnesses, “both mental and physical,” that require constant treatment.

Diana Ellis, her British lawyer, told the court her client presented no risk of fleeing the country if freed.

“The constant need for medical attention, her infirmity, all mitigates against any sensible suggestion that she would flee the country,” she said.

The suspect is the sister-in-law of Khmer Rouge supreme leader Pol Pot, who died in 1998, and wife of Ieng Sary, the regime’s deputy prime minister and foreign minister, who is detained on charges of crimes against humanity and war crimes.

In a detention order issued in November, the tribunal’s investigating judges said Ieng Thirith is to be tried for supporting Khmer Rouge policies and practices that were “characterized by murder, extermination, imprisonment, persecution on political grounds and other inhuman acts.”

She rejected the charges as “100 percent false,” according to the detention order.

Ieng Thirith followed her husband into the jungle to flee government repression in 1965. Their communist movement later became a guerrilla force that toppled the pro-American government in 1975, turning the country in a vast slave-labor camp, with anyone deemed bourgeois executed or imprisoned.