Organizers of China's National Games said Friday that they had returned all sponsorship fees from tobacco companies.

The organizing committee of the event sent a circular to the tobacco control office of China's Center for Disease Control Friday, saying it had returned all the money to tobacco companies.

The circular came after the office issued an open letter on Wednesday, saying the money violated international regulations on accepting sponsorship money from tobacco companies.

At least nine domestic tobacco companies had donated to the National Games that was officially kicked off Friday evening in Jinan, capital of eastern Shandong Province. Among the sponsors, Shandong Tobacco Group offered 20 million yuan (2.93 million U.S. dollars), according to the official website of the sports event.

"We appreciate the National Games' efforts in supporting China's tobacco control campaign," said Yang Jie, deputy director of the tobacco control office.

However, an official with the organizing committee of the sports event, did not disclose the amount of the sponsorship money it had returned, saying he was busy preparing for the opening ceremony of the four-year event.

China signed World Health Organization's Framework Convention on Tobacco Control (FCTC) in 2003 and began to ban tobacco advertising, promotion and sponsorship at domestic and international events since the document took effect in the country in 2006.

China has more than 300 million smokers, the world's largest population. About 1 million Chinese die of tobacco-related diseases every year. The number of victims would increase to 2 million by 2025 if the trend maintains.

In July, organizers of the 2010 World Expo in Shanghai turned down a 200-million-yuan (29.3 million U.S. dollar) sponsorship deal from a tobacco company.