People queue to buy iPad 2 at an Apple store on May 6, 2011 in Shanghai, China.

Authorities have seized Apple iPads from retailers in a city in northern China due to a dispute with a domestic company that says it owns the iPad name, an official said Monday. The Chinese company said it is asking for similar action in more than 20 other cities.

The dispute with Shenzhen Proview Technology threatens to complicate Apple's efforts to sell its popular tablet computer in China, its fastest-growing market.