Argentina’s authorities arrested four suspected members of a gang, two of them from China, who allegedly targeted Chinese establishments for extortion in the area around Buenos Aires.

In response to complaints by merchants in the area, police detained four men who were traveling by car near San Miguel del Monte, approximately 118 km southwest of the capital. The police confiscated a 22 calibre revolver, 30,000 pesos (about $7,300), some ecstasy pills, dozens of cell phones, and various cell phone chips, along with various notes demanding money, written in Mandarin, according to reports.

Over 80 Chinese businesses in Buenos Aires and the nearby province of the same name have allegedly been extorted by the group. Most received threatening notes under the doors of their establishment demanding money in exchange for “protection.”

“Chino, if you don’t deposit $50,000 you will be the victim of a crime,” reads one such note.

The detainees were all between the ages of 24 and 29, two of them from the Chinese province of Fingui, and the other two Argentine nationals.