Three North Korean women, who fled from a restaurant where they worked in China, may arrive in South Korea as early as this week, a source familiar with North Korean affairs said Monday.

The North Korean women in their late 20s and known to be seeking to defect, are staying in Thailand, awaiting to board a flight to Seoul, after escaping a North Korean-run restaurant in the Chinese northwestern province of Shanxi, according to the source.

"They may arrive in South Korea as early as this week," the source said. "As they don't possess passports, South Korean authorities are believed to be seeking cooperation with relevant organizations there."

The latest development is the second of its kind after a group of 13 North Korean restaurant workers defected en masse to South Korea in April.

Last month's defectors worked at a restaurant in the Chinese eastern port city of Ningbo before they arrived in South Korea, with government insiders hinting at tougher international sanctions and mounting pressure by Pyongyang to earn money forced them to escape.

The South Korean government confirmed last Tuesday that an unspecified number of North Korean restaurant workers have recently fled their workplaces, but it declined to reveal details, citing their safety and diplomatic impact.

South Korea's unification ministry also declined to comment on details about the workers on Monday.

"There is nothing that I can further confirm as the (process of their defection) is still underway," Jeong Joon-hee, ministry spokesman, told a regular press briefing when asked about the three people's health conditions.

Pyongyang has claimed that South Korea kidnapped the group of North Koreans who defected to Seoul last month, calling on Seoul to immediately send them back home. Seoul said that the North Koreans defected on their own free will.

Overseas restaurants operated by North Korea have served as one of the main sources of hard currency for North Korea, with which the North is suspected of bankrolling its nuclear and missile programs.

Such restaurants are known to be facing financial difficulty after the U.N. Security Council slapped tougher sanctions on Pyongyang for its January nuclear test and long-range rocket launch in February.

South Korea estimates that North Korea is running approximately 130 restaurants in around 12 countries, including China, Vietnam and Cambodia, earning $10 million annually. (Yonhap)