The Seoul government plans to appeal to international bodies over the fate of nine North Korean defectors who were expelled from Laos and face harsh punishment back home, sources said Wednesday.

The seven men and two women aged between 15 and 23 were caught by Laos authorities while trying to reach the South Korean Embassy on May 10. They were sent to China late Monday and are believed to have been repatriated to their suppressive homeland Tuesday, a Seoul official said.

Vientiane agreed to hand them over to Seoul diplomats but the North Korean Embassy apparently stepped in and demanded their custody, sources said. The defectors and officials together flew to Beijing late Monday with transit visas and could have already touched down in Pyongyang.

“The case can be brought primarily to the U.N. Human Rights Council through the Geneva-based mission,” a diplomatic source told The Korea Herald on condition of anonymity due to the sensitivity of the matter.

“They may address Laos’ decision to transfer them to North Koreans despite knowing they will be subject to penalty back home. As for North Korea itself, its treatment of repatriated defectors could come into question.”

The UNHRC has long criticized the communist regime’s “grave, widespread and systemic” human rights breaches.

In March, the 47-nation body approved its first-ever formal inquiry mechanism into rapes, torture, public executions, slave labor, abductions and other atrocities believed to be imposed on deported defectors and other political inmates at its sprawling prison camps across North Korea.

Along with Thailand, Laos has become a major transit point for North Korean asylum seekers heading to the South and so far maintained sound cooperation with Seoul.

The ruling Saenuri Party said it has sent a written protest to Vientiane and urged Seoul to step up diplomatic efforts.

“The government has to make sure that relevant countries will not repatriate defectors and treat them as illegal migrants but send them to South Korea,” party chairman Hwang Woo-yea told a meeting of senior members.

He called on the Foreign Ministry to investigate any possible lapses and hold those in charge accountable.

“There has been a constant stream of reports from nongovernmental organizations that North Korea harshly punishes its people such as for religious activities,” Hwang added, stressing the need to refer the cases to the U.N.

With a brewing political and diplomatic backlash here, the ministry swiftly set up a task force on Monday night under Deputy Foreign Minister Lee Kyung-soo.

Foreign Minister Yun Byung-se has also been convening meetings with senior officials since then to discuss future handling and ways to prevent a recurrence.

“This incident is deemed very peculiar given Laos’ active cooperation over the past seven years. Any other country in the region has turned over defectors to the North Korea side,” a diplomatic source said, requesting anonymity due to the sensitivity of the subject.

The unprecedented incident appears to reflect Pyongyang’s still formidable influence on the socialist Southeast Asian country and tightening crackdowns on defectors since Kim Jong-un took power in December 2011.

The two countries established diplomatic relations in 1974. The North’s ruling Workers’ Party has beefed up exchanges with the Lao People’s Revolutionary Party.

In June 2008, they clinched an agreement to boost cooperation on civil and criminal cases and social safety. Last year, then-powerful General Staff Chief Ri Yong-ho and Supreme People’s Assembly president Kim Yong-nam visited Vientiane in May and August, respectively.

Meanwhile, Pyongyang’s young ruler has reportedly been stepping up border control since early last year.

Open Radio for North Korea reported in July that the regime had mobilized about 20,000 extra soldiers to border areas, warning severe punishment for those who get caught fleeing.

China, for its part, has taken flak for sending back home North Korean refugees under their decades-old pact, calling them “illegal economic migrants.”

In March 2012, Beijing launched a nationwide clampdown on foreigners who illicitly crossed the border, obtained jobs or overstayed their visas.

With tens of thousands of North Koreans believed to be hiding in China, concerns have grown that they could become more exposed to abuses.

“There are some issues that have a negative impact on relations with China, namely of defectors,” Seoul’s new Ambassador to Beijing Kwon Young-se told a news conference later in the day.

“I will strive to sufficiently persuade China of the treatment that they receive upon return to North Korea and strongly request China’s support on the humanitarian aspect as a global power so that we can smoothly resolve the defector issue.”

More than 24,000 North Koreans have settled in the South since the end of the 1950-53 Korean War, according to the Unification Ministry.

The figure steadily rose from 1,383 in 2005 to 2,927 in 2009, although it slid to 2,376 in 2010 due to reinforced border security.

By Shin Hyon-hee (heeshin@heraldcorp.com)