China has resumed construction of the 100,000 seat "bird's nest" national Olympic stadium, designed as a centerpiece venue for the 2008 Olympics in Beijing, reports said Tuesday.

The Beijing Times said that a resumption ceremony was held on Monday morning and some digging machines and trucks have started to work on the construction site.

The stadium will host the opening and closing ceremonies and the track and field competition during the 2008 Olympics.

But the stadium, with bands of steel stretching every which way to resemble a bird's nest, was designed by Swiss architects Jacques Herzog and Pierre de Meuron.

Reports have put the budget for the stadium at three billion yuan (about 362.4 million U.S. dollars) on December 24 last year, but the figure had grown to 3.5 billion yuan (about 422.8 million U.S. dollars).

The Chinese government then halted the costly construction on July 31 to optimize the design.

Zhu Jin, a media official from the Beijing Organizing Committee for the 2008 games, has said: "The overall style of the stadium won't be changed."