SEOUL, SOUTH KOREA - Activists are urging China not to repatriate seven North Koreans who were detained in an eastern Chinese province after leaving their homeland.

The group, which includes a nine-year-old girl, fled North Korea last month but was detained by Chinese authorities in the northeast province of Liaoning, according to activists.

China regularly sends defectors back to North Korea, where they face punishment including forced labor, imprisonment, torture, or execution.

About two dozen activists, including many who also fled North Korea, protested Tuesday in front of the Chinese embassy in Seoul, urging Beijing to release the group.

The nine-year-old girls mother, who left North Korea several years ago and now lives in South Korea, also attended the demonstration.

Im worried about my young daughter and her safety ... its been three years since Ive seen my daughter, said the woman, her voice quivering.

The woman, who did not wish to be identified, left a message in the Chinese embassys mailbox. An activist also shouted into the intercom outside the embassy entrance, but received no response.

Former senior North Korean diplomat Thae Yong-ho, who defected with his family to South Korea in 2016, helped organize the protest.

We should not let Chinas government repatriate their nine-year-old daughter back to North Korea, said Thae, who made appeals in Korean, Chinese, and English.

Thae, one of the highest level North Korean officials to defect in years, also urged the U.S. government to exert its influence on China to release the North Koreans.

The number of North Korean defectors has declined, in part because of China's expanded crackdown. In 2018, just 1,137 North Koreans defected to South Korea, according to Seouls Unification Ministry. In 2009, that figure stood at 2,914.

Though China has signed the United Nations refugee convention, it does not recognize North Koreans as refugees. It instead sees them as illegal economic migrants.

According to a 2017 Human Rights Watch report, China has increased the number of guards and laid more barbed wire fencing along the border.

China has also expanded CCTV surveillance on the border and increased checkpoints on roads leading away from the border, the group said.

Though not common, China has in the past released North Korean defectors. In 2018, China freed 30 defectors, following international pressure, according to South Korean media reports.

Many activists complain North Korean human rights have become less of a priority amid negotiations over North Koreas nuclear weapons program.