WASHINGTON (Yonhap) -- Shin Dong-hyuk, born and raised in a North Korean concentration camp, on Tuesday appealed for the world to care more about the ongoing tragedy of political prisoners in the communist nation.

He warned that a Holocaust-style slaughter could occur there any time if people outside continue to turn a deaf ear to the testimony of defectors.

"There is a place I always visit whenever I come to Washington D.C. It's the Holocaust Memorial Museum. Watching video footage, I imagine the future of political prisoner camps in North Korea," Shin said at a forum here.

The 31-year-old said he had been forced to witness the public execution of prisoners twice a year, living in Camp No. 14, about 55 miles north of Pyongyang.

"Those who carry out such public executions, I think, have a sufficient capability to kill prisoners en masse if something happens to North Korea," he added.

Shin was born in the camp and remained there for 24 years before jumping over electrified fences and escaping to China. He settled in South Korea in 2006.

He has stepped into the U.S. media spotlight since the publication last month of "Escape from Camp 14," a book on his experience by American journalist Blaine Harden.

Shin confessed his mother and brother were executed in Camp No. 14 because he tipped the authorities to their wrongdoings.

"At that time, they were just other inmates for me as I had no concept of family," he said.

Shin's story has not been independently verified, with the North tightly controlling the flow of information and access by foreigners.

But he emphasized that the international community should not waste more time waiting for "proof" of what is happening in the North.

"I am appealing to you; Do not just look at people who are helpless and passing away," he said. "I have hope that the North Korean regime will move even a little bit if the international community speaks up and puts pressure on it."

Harden, who used to work at the Washington Post, also said the U.S. people need to pay closer attention to the issue.

The bad news is most Americans do not know about the situation in the North's prison camps. The good news is they become keenly interested when they are informed of it, he pointed out.

Meanwhile, a new report on the matter was released at the one-day conference, organized by the U.S. Committee for Human Rights in North Korea and the Jacob Blaustein Institute for the Advancement of Human Rights.

An estimated 150,000 to 200,000 North Koreans are incarcerated in a hidden, Soviet-style gulag, according to the 229-page report by David Hawk, a human rights specialist with the committee.

The report, based on the testimony of 60 former North Korean prisoners and former guards, provides details of human rights abuses in those camps, with satellite images of relevant facilities attached.

Inmates, imprisoned without judicial process, are held behind barbed wire and electrified fences and are subject to forced labor in mining, logging or agriculture, it says. The death rate is very high due to executions, torture and malnutrition, it added.

More than 300 people attended the event at the Peterson Institute for International Economics. Participants included Glyn Davies, the U.S. special representative for North Korea policy, Robert King, the U.S. special envoy for the North Korean human rights, Rep. Park Sun-young of South Korea's conservative minor Liberty Forward Party, and Hwang Joon-kook, minister at the South Korean Embassy in Washington.

Davies said he was "fascinated and impressed" by Shin's story.

"I am here to learn" about the North's situation, he told Yonhap News Agency.