China and Vietnam will expand intelligence sharing and case investigations in the fight against rampant cross-border trafficking of women, a senior Ministry of Public Security official said.

The ministry has said that the number of such cases dropped slightly last year thanks to the two countries’ intensified efforts, but it did not release details.

“We’re still engaged in a bitter battle to eliminate cross-border human trafficking, which arises out of unbalanced economic development and loopholes in social management,” Chen Shiqu, deputy director of the ministry’s Criminal Investigation Department, said recently in an exclusive interview.

Chinese and Vietnamese police have agreed to promptly exchange information and clues and to conduct joint investigations in their efforts to smash major human trafficking rings.

They are tightening border management and intensifying inspections along the border to close channels for human trafficking. And they are focused on improving the efficiency of their cooperation in investigating and evidence gathering, in capturing and repatriating suspects, and in rescuing victims.

In recent years, a number of mostly poor, rural Vietnamese women have been kidnapped and smuggled into China to enter into forced marriages or prostitution. Some were tricked into coming by promises of large salaries, according to the ministry.

Chen said the victims are often sold in rural China as brides or forced to provide sexual services in clandestine dens in costal or border areas in, among others, Guangdong and Yunnan provinces and the Guangxi Zhuang autonomous region.

Chinese traffickers have long collaborated with Vietnamese associates in the trade, he said. Gangs are formed with members tasked with recruiting, arranging the smuggling and visa services, and contacting buyers to form a complete criminal chain.

Vietnamese traffickers usually look for rural women in their 20s and 30s and persuade them to travel to China with promises of high-paying jobs or touristic trips, said Chen Jianfeng, director of the anti-human trafficking office in the Criminal Investigation Department.

He said some criminals have even set up illegal cross-border marriage agencies and tell the women they will become brides of rich Chinese men in big cities.

When the women agree, they are smuggled into China along small forest roads or mountain areas or across the river, said Jin Yulu, a police officer at the Ruili checkpoint in Yunnan’s Dehong Dai and the Jingpo autonomous prefecture.

Upon arriving China, the women are handed over to the traffickers Chinese accomplices, who then take charge of providing accommodation and connecting agents, transporting or trafficking them across the country, Chen Shiqu said.

The cost of a Vietnamese woman ranges from 60,000 to 100,000 yuan ($8,700 to $14,500), depending on her age and appearance, he said.

Last May, police in seven provinces and municipalities, including Yunnan, Jiangxi and Shanghai, conducted a coordinated action to smash a large cross-border women trafficking ring. Seventy-five suspects were captured and 35 Vietnamese women rescued, according to the ministry.

In February, Vietnamese traffickers targeted young girls and lured them to the Chinese border. Chinese traffickers then contacted agents and sold the girls for huge profits.

After receiving tips, police succeeded in smashing the major cross-border women trafficking ring. One buyer, surnamed Wang, from Henan, was caught as he selected a bride in Yunnan. Wang said he bought a Vietnamese bride because his family was too poor for him to be able to marry a Chinese woman.

Chinese and Vietnamese police mounted a special action against rising cross-border trafficking of women for three months last year. During the action, Chinese police uncovered 184 trafficking cases, and arrested 290 suspects, according to the ministry.

Sixty-one criminal gangs were smashed and 207 Vietnamese women plus one child were rescued, it said.

Last week, 13 suspects went on trial in Yunnan. They stood accused of trafficking or purchasing 27 Vietnamese women and bringing them to China for forced marriages between July 2014 and April 2016. The verdicts are pending.

Chen Shiqu said China has set up an annual meeting of senior officials to combat international trafficking. Eight border offices with neighboring countries, including four offices in Vietnam, have been set up to aid in the effort.

Chinese authorities will take great care to protect the legitimate rights of the rescued female victims and will see to their settlement in temporary shelters and ultimate repatriation, he said.

And each year, he added, we will conduct extensive campaigns with Vietnam to eliminate cross-border human trafficking.