BEIJING — Airlines are being told to stay away from Beijing's airport during the opening ceremony of the Olympics and further scrutiny is being applied to foreign entertainers in the latest moves ahead of next month's games

The airport will close for about four hours during the opening ceremony, affecting dozens of flights.

But a spokesman from the airport denied the reports, saying they welcomed all flights to Beijing. He would not want to give his name, as is common with officials in China.

The warning for the entertainers appears to be part of a wide-ranging set of measures China has put in place ahead of the Olympic Games to stop not only political protests but also physical attacks.

Performance rules, which were first introduced in 2005, are being reinforced to guard against entertainment that could tarnish the country's carefully cultivated image of order and control. Authorities were alarmed in March after Icelandic singer Bjork shouted "Tibet! Tibet!" at the end of her concert in Shanghai.

Authorities said her outburst "broke Chinese law and hurt Chinese people's feelings," and vowed to be stricter on foreign performers.