PHNOM PENH: Two Khmer Rouge leaders were jailed for life Thursday after being found guilty of crimes against humanity, the first sentences against top figures of a regime responsible for the deaths of up to two million Cambodians.

Neither “Brother Number Two” Nuon Chea, 88, nor former head of state Khieu Samphan, 83, betrayed any hint of emotion as the sentences were handed down at Cambodia’s UN-backed tribunal.

But outside the court on the outskirts of Phnom Penh, regime survivors burst into applause with many weeping after a 35-year wait for justice.

Judge Nil Nonn said the defendants, who are the most senior surviving Khmer Rouge leaders, were “guilty of the crimes against humanity of extermination... political persecution, and other inhumane acts.”

Their lawyers swiftly announced their intention to appeal the conviction, but the court earlier ruled the pair would remain in detention until a final judgment due to “the gravity of the crimes.”

Prosecutors had sought the maximum life terms for the men, who played key roles in a regime that left around a quarter of the country’s population dead during the “Killing Fields” era from 1975-1979.

Led by “Brother Number One” Pol Pot, who died in 1998 without ever facing justice, the Khmer Rouge dismantled modern society in their quest for an agrarian utopia.

Regime atrocities affected virtually every family in Cambodia as Pol Pot’s peasant army — infamous for their red chequered scarves and dark clothing — slaughtered perceived enemies of the revolution and emptied towns and cities at gunpoint to work in the fields.

The plan spectacularly backfired, leading to the collapse of the economy and mass starvation.

Nuon Chea, wearing his trademark sunglasses, sat in a wheelchair in the dock as the verdict was read, while Khieu Samphan stood impassive next to him.

Late in their two-year trial both men expressed remorse for the suffering the Khmer Rouge inflicted on Cambodia, but remained staunch in denying knowledge of its crimes at the time.

The ruling is likely to bring a level of relief to those who survived the Khmer Rouge years, which saw Cambodians wiped out by starvation, overwork, torture or execution by ruthless cadres.