BEIJING, July 27  A violent protest erupted last weekend at a factory in southern China that makes toys for McDonald’s and other international companies, a rights group said Thursday, and the local police were called to the scene to restore order.

China Labor Watch, a New York-based labor rights group, described in a news release a riot by more than 1,000 workers protesting low pay and poor living conditions at the factory in the industrial city of Dongguan. However, a distributor for the factory said the unrest was not about wages or conditions but was instead prompted by a disgruntled worker who had been laid off.

Efforts to reach factory workers on Thursday were unsuccessful. A police officer in Dongguan confirmed by telephone that officers had been summoned to the factory, but he refused to describe what happened.

An account of the matter posted at Tianya Club, a popular Chinese Internet forum, told of a violent clash between workers and security guards that had spilled out of two dormitories. The anonymous writer said workers had opened fire hydrants to push back guards and cars were overturned and computers smashed until the riot police finally took control of the factory.