Chinese police handed over seven escaped Vietnamese brides married to Chinese bachelors to Vietnamese police on Thursday afternoon in Guangxi Zhuang autonomous region, China News Service reported on Friday.

The women were bought as brides from Vietnam, and were married to Hebei bachelors. They had been living in the local villages. The brides' ages ranged from 17 to 32-years-old.

At the end of November, about 100 Vietnamese brides vanished in Hebei province. Local police began their investigation on the disappearance of the brides.

Police arrested key members involved in bride trade business in December and found some of the missing Vietnamese women.

The women were married to local bachelor villagers through a “broker”. The grooms would pay a large amount of money for a successful matchmaking.

Yuan Xinqiang is one of the Chinese grooms.

Yuan, 22, from Quzhou county of Handan, Hebei province, was waiting and expecting his newly-wed Vietnamese wife to return home voluntarily. He still could not believe that his Vietnamese sweetheart had ran away.

Yuan married a Vietnamese woman in September after being introduced to her by Wu Meiyu, a Vietnam bride who has been living in another village in the county for about 20 years.

Yuan paid Wu 105,000 yuan ($17,000).

According to the police, Wu is a criminal.

"Since Wu had been in the village for a long time and has a 6-year-old grandson, I didn't expect she would cheat me out of my money," Yuan said, adding that the bride was gentle and quiet and had won his trust.

Wu has disappeared, together with all the brides she introduced. Her only remaining family member is her father-in-law, who said Wu had gone abroad to arrange residency permits for the Vietnamese brides so they could settle in China.

A public servant of Handan, who declined to be named, said there might be an organized ring that helped all the brides leave en masse.

"With the advanced communication techniques of today, it's easy for all the brides to leave at the same time," he said.

The official said buying brides has developed into a local ritual in rural areas such as Guantao and Wei counties.

China's stringent family planning policy, which has resulted in more male births due to a traditional preference for sons, is causing a widening gender gap, the official said, adding that as the gap widens, the cost of a Chinese bride moves beyond the budget of local farmers.

A villager surnamed Xu, of Guangping county, said it's customary for a man to offer 110,000 yuan in cash and a car worth at least 40,000 yuan as betrothal gift. A groom is also required to own a house. So the cost of marrying a Chinese woman could reach as much as 400,000 yuan.

"Since most bachelors cannot afford to marry a local woman, they take Vietnamese brides," Xu said.

The public security bureau of Handan said international matchmaking services and cross-border marriage brokerages are illegal, and the case may be related to human trafficking. It remains unclear the total number of Vietnamese brides who had been found and the number, if any, that have returned to their Chinese husbands. According to the China News Service, some had been departed and transferred to Vietnamese police.

Luo Wangshu and Zhang Yu contributed to the story.