MALAI, Cambodia: Hundreds of mourners massed Thursday ahead of the cremation of a co-founder of Cambodia's Khmer Rouge, highlighting the stark divide between supporters and victims of the brutal communist regime.

Former Khmer Rouge foreign minister Ieng Sary, 87, died last week while on trial for war crimes and genocide, cheating Cambodians of a verdict over his role in the regime's 1975-1979 reign of terror.

About 500 people -- including relatives, former Khmer Rouge fighters and chanting monks -- gathered for a ceremony on Thursday morning, with more people expected to attend the cremation outside the home at 6:00 pm (1100 GMT).

Many in the crowd which gathered in Ieng Sary's home town of Malai near the Thai border wore black and white mourning dress, and black ribbons pinned to their chests.

"He is a hero for the people of Malai," said former Khmer Rouge cadre Long Run, 78, describing the regime co-founder as a "patriot" who defended the country from Vietnamese invaders.

"I was shocked when I heard he was dead. We're sorry that we lost him now," he told AFP as he paid his respects at Ieng Sary's home in Malai, a small bustling town where former Khmer Rouge cadres sell goods in a local market.

A large picture of Ieng Sary was placed next to his golden coloured coffin -- surrounded by flowers -- where mourners came to pay their respects.

A Buddhist monk shaved the heads of his son Ieng Vuth and several other relatives during a religious ceremony that was also attended by the late regime leader's international defence lawyers.

His widow Ieng Thirith, the regime's former social affairs minister, arrived later dressed in white, and was carried into the house.

Initially a co-defendant alongside her husband, she was freed in September after being deemed unfit for trial due to dementia and lives in Phnom Penh.

The death of Ieng Sary, one of the regime's few public faces, intensified fears the remaining two elderly co-defendants may also die before verdicts can be reached in their trial, which began in June 2011.

"Justice for the victims is fading little by little," said Bou Meng, 72, one of a handful of people to survive incarceration at the Khmer Rouge's Tuol Sleng prison in Phnom Penh.

He reacted angrily to the mourning for Ieng Sary in his powerbase in the remote northwestern border area, where he held out with fellow Khmer Rouge members after the regime fell from power until his defection in 1996.

"Regarding him as a hero is totally wrong," Bou Meng said. "He is a killer."

Several hundred villagers attended a funeral ceremony last Friday. Some wept, according to witnesses, even though Ieng Sary was accused of overseeing purges and the murder of intellectuals as foreign minister.

"Although people from outside this area accused him of genocide, he did good things for the poor people here," said former regime cadre Nhem Preuong, 58.

The one-time radical student was the oldest of three former leaders on trial, along with "Brother Number Two" Nuon Chea, 86, and former head of state Khieu Samphan, 81.

All denied charges including war crimes, genocide and crimes against humanity.

Led by "Brother Number One" Pol Pot, who died in 1998, the Khmer Rouge killed an estimated two million Cambodians through starvation, overwork or execution in a bid to create an agrarian utopia.

So far the UN-backed court -- which has been dogged by allegations of political meddling and frequent funding problems -- has achieved just one conviction, sentencing a former Khmer Rouge prison chief to life in jail.

"The court must speed up the trial," said Bou Meng. "I deserve some kind of justice while I'm still alive."