Chinese police have rescued 77 children and arrested 310 suspects after busting four child trafficking rings, the Ministry of Public Security said yesterday.

More than 7,000 police officers from 14 provincial areas, including Shandong, Guizhou, Henan, Shanxi, Yunnan and Guangxi, took part in a joint operation, busting the trafficking networks early on Wednesday morning, according to a statement on the ministry's website.

It said that last October police in the eastern Shandong Province gained information about two separate trafficking gangs buying infants from Yunnan, Guangxi and Shanxi, among other areas, and selling them to clients in Shandong.

Around the same time, police in the southwestern Guizhou Province discovered two other trafficking gangs.

The ministry set up a special team and after more than five months of investigations, police from the regions involved launched a joint raid.

Human trafficking is a serious problem in China with numerous cases of young women being kidnapped from poor southwestern regions and sold to rural families in faraway provinces over the past decade. Generally, the women are married off to desperate bachelors, while babies, preferably boys, are mostly sold to sterile couples not qualified to adopt children.

Official figures show that last year, police rescued 8,660 abducted children and 15,458 women in busts of 3,195 human trafficking gangs.

Meanwhile, greater efforts are being made to discourage would-be buyers. "Rescued children will no longer be kept by families who have paid for them, making buyers lose both the child and the money," the statement said.