Apple supplier Pegatron Corp reported an explosion at a subsidiary’s plant in Shanghai over the weekend that injured 61 workers.

Pegatron Chief Financial Officer Charles Lin told “Reuters” (http://macte.ch/7XAxB) that the explosion at the plant, which belongs to Riteng Computer Accessory Co and is located in Shanghai’s Songjiang industrial park, had not caused a fire, but 23 of the injured workers needed to be hospitalized. The factory has not started operations yet, he added. Part of the facility is still under pre-operation inspection and part is running trial production.

Apple said it was investigating. “Our hearts go out to the people who were hurt in Songjiang,” spokeswoman Carolyn Wu told “Reuters.” “We are working closely with Pegatron to understand the cause of this accident.”