A Pakistani court has convicted two Chinese nationals for tampering with an ATM machine, sentencing each of them to a year in prison and a fine of around $400.

Akbar Khan, a cybercrimes investigator, said Monday that Zhong Xiaming and Zhong Xianquan were arrested a year ago while attaching a skimming device to an ATM in Karachi. The devices are placed over ATM slots and scan the magnetic strips of cards when customers insert them. They are often used in conjunction with hidden cameras that can film PIN numbers.

Khan says cybercrimes investigators have arrested another six Chinese nationals in recent months who are alleged to have used skimming devices. Similar incidents were reported in other Pakistani cities.