Hong Kong ? Dozens of workers were detained after a two-day protest over pay and working conditions at a toy factory, a labor monitoring group reported Thursday.

The protest at the Merton Co. plant in the southern city of Dongguan began in the company dormitory Saturday, according to China Labor Watch, a group run by Chinese exiles based in New York.

Police were sent in, but the protest by hundreds of workers continued until Sunday, the group said. It gave no information about any injuries or damage.

Police, government and labor union officials said they had no information about the protest. Phone calls to Merton’s corporate headquarters in Hong Kong seeking comment were not immediately returned.

Dongguan, just across the border from Hong Kong, lies at the center of China’s export manufacturing industry, which relies heavily on low wages to remain competitive.

Salaries start at $72 a month for the factory’s roughly 11,000 workers, China Labor Watch said. But about half that amount is deducted for meals and lodging, and workers face pay cuts if they refuse to work up to 70 hours of overtime a month.