Two Vietnamese women trafficked to China with promise of good jobs were repatriated to Vietnam by police in Hefei, Anhui province, in this 2014 file photo. [Photo/CFP]

BEIJING -- China's railway police have arrested 18 suspects allegedly involved in international women trafficking, rescuing 12 Vietnamese women.

The suspects belong to two human trafficking groups, according to a statement of the railway police on Monday.

Railway police launched the investigation after a suspect surnamed Li was found trafficking a Vietnamese woman on a train running from Kunming, capital city of Yunnan province to Jinan, capital city of Shandong province on December 12.

In the following five months, a special team seized another 17 suspects in Yunnan and Hunan provinces and rescued the other 11 Vietnamese women in Hunan Province.

According to the statement, since 2014, members of the two gangs crossed the border into Vietnam illegally and conned Vietnamese women into China by pretending that they were offering recruitment and matchmaking services. Once the women were in China, they were taken into Hunan and sold.