Police in Croatia and Slovenia say they have busted a human trafficking operation and released dozens of mostly Chinese nationals who were forced to work in illegal call centers.

Croatian police said Saturday they have detained two Croatian and two Chinese citizens accused of running the fraud scheme from two houses in greater Zagreb, the capital.

A police video shows officers breaking into one of the houses and finding the locked Chinese nationals who had been stripped off personal documents and kept inside. Police say some 60 people were found.

Earlier this week, Slovenia's police said they have found 32 people on several locations, and detained two Slovenian citizens and four Asian nationals.

Police say illegal call operators sought to persuade people to transfer money to other accounts.