SHANGHAI, Aug. 6 -- FOOD for Olympic athletes and at Olympic villages will have digital codes as part of a supervision system to ensure its safety, said a senior official with the Beijing organizing committee today.

"The codes will help us track food producers and transporters," said Wang Wei, secretary general with the committee, during a press conference in Beijing today.

Vans to transport Olympic food will be equipped with GPS systems. The vehicles will automatically record the temperature and humidity inside and transmit the information back to bases.

"It will be an around the clock supervision system of food safety," Wang added.

Wang quoted a figure from a program on China Central Television yesterday that said 99 percent of food exported from China is safe.

"Beijing has successfully hosted many big events," Wang said. "No serious food problems have been reported."

Beijing's government has established a special team to supervise food safety during the Olympics. The team is responsible to indicate, after inspections, which restaurants are safe and hygienic.

Wang also talked about progress in Olympic preparations, including construction of sports venues, ticket selling, traffic and programs designed for the opening and closing ceremonies.

Construction of 36 stadiums and 56 training courses will finish by the end of this year. The main stadium, nicknamed the "Bird's Nest" due to its design, will be ready early next year. It will host the opening and closing ceremonies.

By the end of June, the committee had received more than 720,000 applications for at least 5.1 million tickets, Wang said.

Programs for the two ceremonies have been basically nailed down and rehearsals will start soon, Wang said.

China's famous movie director Zhang Yimou is the general director of both the opening and closing ceremonies.