Four Rio Tinto employees, including Stern Hu, general manager of the company's Shanghai office, were arrested last week for allegedly stealing state secrets.

"The investigation, however, does not mean that we will restrict the operation of foreign companies in China, nor cooperation between Chinese and foreign enterprises," Qin said.

Qin said the government promised to protect foreign companies' legal and just rights.

"Those companies, meanwhile, bear the responsibility of abiding by Chinese laws and regulations," he said.

Rio Tinto has representative offices in Beijing, Shanghai and Guangzhou on the Chinese mainland.