South Korea will seek global support at a UN meeting next week for its efforts to rescue North Korean refugees recently arrested in China and facing repatriation, the foreign ministry said Tuesday.

Activists and Seoul lawmakers say about 30 North Koreans will be returned from China to the secretive state even though they face harsh punishment in their homeland.

The South Korean foreign ministry has not confirmed the total figure.

But a spokeswoman said Seoul has repeatedly urged Beijing not to repatriate at least 10 North Koreans arrested in the northeastern city of Shenyang this month.

"Since our bilateral discussion (with China) is not working very well, we will make efforts to get international support via various channels including the UNHCR (United Nations High Commissioner for Refugees)," she told AFP.

Seoul diplomats will address the broad issue of ensuring safety for North Korean refugees during a UNHCR meeting in Geneva next week, she said, but will not specifically target China for criticism.

Rights groups have criticised China's policy of repatriating North Koreans as economic migrants rather than affording them refugee status.

The spokeswoman also confirmed a media report that 11 North Korean refugees have been trapped in South Korean consulates in Beijing and Shenyang for almost three years because China refuses to let them leave for the South.

"They came in to seek help (from the South). For now, there is no way for them to get out of there," she said.

JoongAng Ilbo newspaper said Beijing was trying to discourage further attempts by North Korean defectors to enter the South's diplomatic missions in China.

More than 21,700 North Koreans have fled since the 1950-1953 Korean War, the vast majority in recent years.

They typically escape on foot to China, hide out and then travel to a third country to seek resettlement in South Korea.

Activists have staged a series of protests in front of the Chinese embassy in Seoul since last week, calling on Beijing to not repatriate the detainees.

Dozens of protesters Tuesday called China "a bystander of torture and public execution" in the North.

A group of North Korean refugees in Seoul called on Beijing to honour the UN's Universal Declaration of Human Rights, saying refugees could face "indefinite torture eventually ending with public execution" if sent home.

"Please give these innocent lives an opportunity to live," the graduates or current students from the Yeomyung School, which educates refugees from the North, said in a statement ahead of another protest outside the embassy Tuesday afternoon.

On Tuesday Park Sun-Young, a lawmaker of the conservative opposition Liberty Forward Party, launched a hunger strike calling for "fundamental change" in China's policy of repatriating refugees.

"I will fight until the end to stop the forced deportation of defectors with my own life," she said in a statement before starting a protest near the Chinese embassy.

The 55-year-old took up a place on a plastic mat outside a church in front of the embassy, with a blanket shielding her from the wintry weather.

Activists say the North has toughened punishment for fugitives as the regime tightens its grip after the power transfer from late leader Kim Jong-Il to his son Jong-Un.