JINAN, Jan. 13 -- Police in east China's Shandong Province have rescued 37 children and identified 103 suspects since 2014 in an ongoing investigation into child trafficking operation, local authorities said Tuesday.

After receiving a tip-off from a member of the public in June 2014, police detained six people for allegedly abducting a child at a local train station.

One of those arrested, Bao, confessed to being active in the group since late 2013 and informed police that the gang had been trafficking babies from Sichuan Province to cities of Linyi and Jining in Shandong since 2012.

In their investigation, police have uncovered a total of eight trafficking rings all led by two suspects identified as Ji and Ma.

In September 2014 about 40 suspects were detained over allegations of selling more than 20 babies.

On September 10, 2014, police also raided a location in Yanzhou City in Shandong and took four suspects into custody. One baby boy was rescued from the scene.

Two suspects, Gong and Wu, confessed to have been cooperating with Ji and had coordinated the purchase of babies from pregnant women.

The Yanzhou group had sold 12 newborns since 2013, according to police.

China has seen many cases of human trafficking in recent years. In March 2013, Chinese police rescued 92 children and two women and detained 301 suspects.