Updated

PHNOM PENH, Cambodia (AP) — The Khmer Rouge's chief jailer plans to appeal his conviction by a U.N.-backed war crimes tribunal, which sentenced him to 35 years in prison for overseeing the deaths of up to 16,000 people, the tribunal spokesman said Tuesday.

Kaing Guek Eav — also known as Duch — was convicted Monday of war crimes and crimes against humanity. He was the first major Khmer Rouge figure to face trial more than three decades after the regime's brutal rule led to the deaths of 1.7 million people.

He will only have to serve 19 years of his sentence after taking into account time already served and other factors.

Tribunal spokesman Reach Sambath said that Duch's lawyer, Kar Savuth, has notified the tribunal of his intent to appeal.

"Kar Savuth told me several hours after the verdict was issued that he would appeal," the spokesman said. "He said he would have appealed a sentence of even one day."

Duch oversaw the notorious Tuol Sleng prison and torture center — code-named S-21. He admitted his guilt during testimony but argued that he was only following orders and acted out of desperation to save his and his family's lives and should not he held responsible.

Survivors of the "killing fields" of 1975-79 expressed anger and disbelief at what they saw as too lenient a sentence for a key player in the regime that wiped out a quarter of Cambodia's population.

Four other senior leaders of the Khmer Rouge are detained and waiting to face trials, expected to start later this year.