A robot went out of control at the China Hi-Tech Fair 2016 in Shenzhen on Thursday, smashing a glass window and injuring a visitor. The robot that went violent is named “Fatty” and is designed for household use.

This is the first time in China that a robot has injured a human being. Some Chinese netizens on Weibo said that they fear the incident signals the start of the "invasion" of robots.

However, the event organizer said human error was responsible for the mishap. The operator of the robot hit the “forward” button instead of “reverse,” according to one of the fair’s organizers.

This command sent the robot off in the direction of a neighbouring exhibition booth that was made from glass. The robot rammed into the booth and shattered the glass, the splinters from which injured the ankles of a visitor at the exhibition.

Details about the injured visitor were not immediately available, according to local media’s reports, but images circulating on the Internet on Friday show what appears to be a middle-aged man lying on a stretcher. After receiving emergency aid on-site, the patient was sent to the nearby hospital by ambulance and was discharged after receiving stitches.