The Tumen River, seen here from Hunchun, China, serves as the border between China and North Korea. (Shin Woong-jae/For The Washington Post)

Human rights advocates are urging China not to repatriate nine North Korean refugees, including an 11-month-old, who were caught while trying to escape the totalitarian regime of Kim Jong Un, warning of the harsh fate that awaits them if sent back.

North Korea is the most tightly controlled country in the world, with ordinary citizens banned from traveling abroad. Those who try to get to South Korea are considered traitors and, if caught and sent back, face severe punishment that almost always involves time in prison camps.

The nine North Koreans managed to cross from North Korea into China in the middle of last month and then made their way down to Vietnam, in hopes of eventually reaching South Korea, according to human rights activists.

This circuitous and highly dangerous route through Southeast Asia has become the most frequently used path to South Korea, where North Koreans can settle and become citizens in a familiar culture.

The group, which includes a teenager, was found during a random check on a bus in northeastern Vietnam — not far from the border with China — and handed over to Chinese police in Guangxi province.

Human rights advocates are asking China not to send the group back to North Korea.

“There is little doubt that if these nine refugees are forced back to North Korea, they will disappear into a camp system characterized by torture, violence and severe deprivation from which few emerge,” said Phil Robertson, of Human Rights Watch. “If China sends them back to North Korea, they could well be sending them to their deaths.”

The United Nations voiced similar concerns.

“There are fears that they may be — or may already have been — repatriated to [North] Korea, where they would be at risk of very serious human rights violations,” Ravina Shamdasani, a United Nations human rights spokeswoman, said in a briefing in Geneva, according to Reuters.

Human rights groups report that the refugees were sent by train to the northern Chinese city of Shenyang last week and then transferred to Tumen, on the Chinese side of the border with North Korea. There is a large detention facility in Tumen where North Koreans are held before being repatriated.

This did not bode well, Shamdasani said. “This series of events strongly suggests that the group is at imminent risk of being repatriated to [North Korea] — and we are gravely concerned that they may already have been returned,” she said.

Signatories to the 1951 Refugee Convention and its 1967 Protocol, which include China, are banned from “refoulement” or returning refugees to a country where they could be persecuted.

But China considers such escapees from North Korea to be economic migrants, not political refugees, so it sends them back. There is no indication that Vietnam gave the group the opportunity to lodge asylum claims there, Robertson said.

The 2014 report by a U.N. Commission of Inquiry described the punishment meted out to North Koreans who try to escape.

“When they are apprehended or forcibly repatriated, officials from [North] Korea systematically subject them to persecution, torture, prolonged arbitrary detention and, in some cases, sexual violence, including during invasive body searches,” the commission’s report said, noting that pregnant women were regularly forced to have abortions.

“Persons found to have been in contact with officials or nationals from [South] Korea or with Christian churches may be forcibly ‘disappeared’ into political prison camps, imprisoned in ordinary prisons or even summarily executed,” the report continued.

The number of people successfully making the journey has dropped sharply in recent years, in large part because of a clampdown on both sides of the ­China-North Korea border.

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