Chinese police seized nearly 2 million fake CDs and DVDs when they raided a factory in the country's largest crackdown on entertainment industry pirates, the Xinhua agency said on Tuesday.

The high-tech operation could use 30 machines spread over 11 warehouses to churn out over 300,000 fake discs in one night, Xinhua quoted a top anti-piracy official as saying.

The factory was situated in Guangzhou, capital of southeastern Guangdong province, near Hong Kong.

Li Baozhong, deputy head of the national office tackling pornography and illegal publications, said the factory was located along the Guangzhou airport expressway for easy transportation.

"This case revealed new tricks by the pirates. The criminals erase the production ID code on the discs in order to destroy evidence showing who provided the original discs," Li added.

Police arrested 13 people, Xinhua added.

The U.S. undersecretary of commerce for intellectual property, Jon Dudas, last week said China appeared to be losing the battle against an army of increasingly sophisticated counterfeiters despite an increased drive to combat piracy.

But China last week urged patience from the developed world as it seeks to stop infringements of patents, copyright and other intellectual property.