The targets are married and single women, and children, from Luu Tien Highlands Village in Chieu Luu Comune of Ky Son District, home to Kho-mu ethnic minority people.

Some 148 hourseholds occupy the village, representing nearly 650 people. Police said at least 38 local women have been allegedly trafficked to neighbouring China.

“Victims were invited by some acquaintances to work away from home with the offer of high salaries and better living conditions," said Moong Van Que, a policeman in the village. "Mediators even gave victims’ families some money in advance as security. They did not return home or contact with their families after their leave,”

Notably, many local children have recently gone missing after leaving home for boarding schools. The number of such children has reached 16. Some are primary students while others are secondary students. The situation has triggered worries among parents that they might have been kidnapped and smuggled to China.

Cut Thanh Son, head of Luu Thang Highlands Hamlet of the same commune, said the village has reported nearly 50 missing people. “Many people have yet to make any contact with their homes while some others have called home informing that they have got married with Chinese men.”

A man and his son care for his grandson after his daughter and daugher-in-law are trafficked to China

A 21-year-old woman from the village was trafficked to China in 2012. She was married to a Chinese man and they have had a daughter. In early 2014, she fled from China to visit her family in Vietnam, but she returned to China, worried about the fate of her daughter.

In another family, a 30-year-old woman was trafficked to China and had a child there. A short time later her husband’s 21-year-old younger sister was offered work in the South, but was trafficked to China and made a concubine. Their family did not have any contact with them until the sister-in-law called home.

“Women trafficking mainly happens in remote and mountainous areas where victims are gullible and too trusting about believing offers of work with high incomes," said Nguyen Truong Thi, head of drug crime prevention and control office under the provincial border guard. "Many traffickers were ever victims of such swindling and return home to seduce others.”

Investigation and prevention efforts are hindered by a lack of funding, Thi said.