Police in Guangzhou arrested eight suspects, detained 30 others and released another two on bail pending trial, after they busted seven criminal gangs allegedly defrauding locals via phone calls and text messages.

Meanwhile police in the city’s Huadu district seized 17 sets of telecommunications equipment, 19 vehicles and 800,000 yuan ($130,000) worth of other equipment used by the gangs, according to a statement from Guangzhou bureau of public security on Tuesday.

“The crackdown has dealt a heavy blow to telephone fraud in the city,” the statement said.

Police urged residents to inform police if they receive suspicious phone calls or text messages.