BEIJING - Remain calm, don't fight back and try to send a text message to the police. That's how Chinese police have advised people to respond if captured by terrorists during next month's Olympic Games, the official Xinhua News Agency said Friday.

The new "anti-terrorism manual" is the latest in a string of warnings issued by an increasingly jittery Chinese government in the run-up to the Aug. 8-24 Olympics. In addition to worries over foreign terrorist plots, Beijing is also concerned about political protests from domestic critics.

China says it fears an attack by Islamic insurgents in the restive western province of Xinjiang, as well as from Tibetans it says who want to split China -- fears brought to the fore by violent riots that erupted in Tibet's capital of Lhasa in March.

A vast security apparatus has been charged with guarding Beijing during the games, including thousands of soldiers, police and anti-terrorist squads. The government has also declared a "people's war" against those who could disrupt the games, enlisting the help of neighborhood watch groups to root out threats.

Xinhua said the manual described potential terrorism threats, including explosions, shootings, hijacking and even chemical or nuclear attacks. It was not clear when the manual, written in Chinese, would be published, or how it would be distributed. China has already repeatedly said that a terrorist attack is one of the biggest worries for the games.

The manual follows a series guides China has published to tell its people how to behave during the games. A training manual for thousands of volunteers working the Beijing Olympics and Paralympics was released in May, on everything from handling visitors to sitting, standing and shaking hands. Campaigns have also been launched to get citizens to form lines in public places stop spitting and improve their driving habits.

China has already installed checkpoints on roads and subway stations around the capital, as well as areas which border Hebei province.

Reflecting China's fears that an attack is possible, Chinese authorities will close Beijing's airport for about five hours during the opening ceremony of the Olympics, affecting dozens of flights, local media and airlines said Friday.

But a spokesman from the airport denied the reports, saying they welcomed all flights to Beijing. He didn't give his name, as is customary among Chinese officials.

Hong Kong-based Cathay Pacific said it would postpone one flight after receiving word that the airport would be closed during the ceremony, set to begin at the auspicious time of 8 p.m. on Aug. 8.

Cathay Pacific spokeswoman Carolyn Leung in Hong Kong said she was informed that Beijing Capital International Airport would be closed from 7 p.m. to midnight on Aug. 8.

A customer service spokesman of Olympic sponsor, Air China, said the airline had also received a notice that the airport would be closed.

Separately, authorities arrested over 1,600 people in Hong Kong, Macau and the southern province of Guangdong over a six-week joint operation targeting Chinese organized crime syndicates active in prostitution and drug trafficking, Hong Kong police said in statement.

Police carried out similar sweeps annually, but they extended this year's by two weeks because of the games, said government-run broadcaster RTHK. Hong Kong is hosting the equestrian events.

On the mainland, authorities have also cracked down on bars and performers. A warning for entertainers, which were first introduced in 2005, was reissued Thursday cautioning against acts 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.

"The content of the performance should not violate the country's law, including situations that harm the sovereignty of the country," the notice said, adding that entertainers also should not harm "national security, or incite racial hatred and ruin ethnic unity."

Live music performances have waned in bars since clubs were told they need a license for live performances.

Will Bernholz, a manager with Kro's Nest, a chain of popular pizza restaurants, said some bars and restaurants were forced to close in the lead-up to the Olympics.

"We've all felt the impact of the Olympics really hurting the social scene ... but people are going to make do, people are going to go where they can," he said.