China Labor Watch, a non profit advocacy group, released a report on Sunday accusing Apple and Foxconn of labor violations related to working conditions at an iPhone factory, Bloomberg reported.

Apple said most of the allegations are false, but acknowledged that its factory had hired more temporary workers than China’s laws permit. 

The China Labor Watch report came just two days before an Apple Sept. 10 event where the company is expected to announce the latest generation of iPhones and other new products. The report’s accusations, including violations related to worker compensation and safety, were based on an investigation into China’s biggest iPhone factory in Zhengzhou.

Over the past decade, Apple has been criticized for harsh working conditions at Chinese factories that manufacture iPhones and other Apple products. In its annual supplier responsibility report, Apple discloses a review of the working conditions at its suppliers’ factories.