BEIJING — With days to go before the Olympics — a time when most host cities are set to offer the world a warm greeting — Beijing seems wary.

Hotels are empty as stricter visa rules keep visitors away. Police in bulletproof vests and with bomb-sniffing dogs prowl roadways. Peddlers have been told to clear off the streets, and unsightly restaurants have been closed. New postal rules prohibit the mailing not only of explosives, but any pastes, electronics and "unidentifiable metal objects."

Even in the hills outside Beijing, farmers who have turned their farmhouses into rustic inns have been told by police to turn away one group of would-be guests. "Foreigners! Oh, that's a bit troublesome," said Sun Fuwang, proprietor of the Spartan Fuwang Farm Home near the tombs of China's last imperial rulers.

Alongside stunning sports venues, new subway lines and floral displays, Beijing is rolling out restrictive measures dampening any festive feeling ahead of the Aug. 8-24 games.

"It's like they're getting ready to throw a great party and then trying to restrain the partygoers," said Bob Dietz of the New York-based Committee to Protect Journalists, who couldn't get a visa despite 20 years of travel to China. "They're not ready to welcome the world."

Chinese officials have defended the moves as necessary to prevent terrorism and keep out what a Foreign Ministry consular affairs official called "hostile forces." The list of disaffected groups is long, from unemployed workers to foreign activists critical of China's policies on human rights.

But the mood contrasts with the lavish, meticulous preparations for an Olympics long billed as the celebration of an open, modern China. It shows just how shaken Chinese leaders are by unforeseen, tumultuous events this year.

Freak snowstorms that paralyzed the south and an earthquake that killed nearly 70,000 people revealed vulnerabilities at home, while a Tibetan uprising against Chinese rule and protests against the Olympic torch relay exposed the government's lack of acceptance abroad. In between, police said they foiled plots by Muslims from China's Central Asian borderlands, one to blow up a Chinese airliner, the other to kidnap Olympic athletes and journalists.

In recent weeks, ordinary Chinese have acidly paired the calamities with the five whimsical Olympic mascots: Beibei the fish with the snowstorms, Jingjing the panda with the Sichuan earthquake, Huanhuan the Olympic flame with the torch relay, Yingying the Tibetan antelope with the Tibet protests and Nini the bird either with a train derailment in April or soaring inflation.

With the games drawing near, the communist leadership called in senior government and provincial officials last month to put them on notice that there should be no security glitches. More than 440,000 people have been mobilized for security for the games, from crack commando squads to neighborhood watch patrols, and leaders are trying to temper public expectations for a superb games.

"In the beginning, the Beijing municipal government says they want to have the best games in Olympic history. Now they say a 'high-quality Olympics with Chinese characteristics.' They have lowered expectations," said Jin Canrong, an international affairs expert at Renmin University. "If the games go without incident, that will be successful."

Beijing's games still could please. The city's $40 billion makeover has transformed the ancient, often dull low-rise capital into a metropolis of 24-hour bustle. Traditional culture puts a premium on being a good host. Normally unruly Beijingers have been told how to cheer for foreign teams and to line up for buses instead of pushing onboard.

All the security efforts are drawing attention to something Chinese leaders have hoped to play down — that China is still a police state, if a chaotic one. They are also raising questions about whether a festive Olympics is possible.

Nightspots near the Worker's Stadium and Worker's Gymnasium, where boxing and other events will be held, have been ordered shut for the games, as a security precaution. Elsewhere, bars and restaurants which often stay open until the last patron leaves, have been told 2 a.m. is the limit.

Rural Chinese who flock to the capital to seek redress for grievances that local officials ignore already have been sent home, while known dissidents have been jailed, put under watch or told to leave.

Arbitrary enforcement of rules, long a staple of life in China, is falling hard on ordinary Chinese. As construction sites are shut down in July to try clear the city's notorious smog, and small restaurants closed for being dirty or other unspecified reasons, many of the city's migrant workers — who make up more than a fifth of Beijing's 18 million people — will be left without pay. Many are leaving.

"Temporarily closed for the Olympic period," read the sign on the Xi'an Cured Meat Buns restaurant, near the Silk Alley market, a tourism hotspot filled with knockoffs of designer clothes. At the also-shut Old Sichuan Homestyle restaurant nearby, an employee said he and his five co-workers were soon leaving for home near Sichuan, out of money.

"Those of us who don't have licenses all have to close," said Zhao Jingchun, a plump, middle-aged laid-off factory worker who runs a small crepe stall to make money. She planned to flout the restrictions. "No matter how strict they are going to enforce the rules, I have to work. I need to eat."

The tighter visa requirements keeping foreigners out have been accompanied by recurring police checks on places where foreigners live and orders for those properly papered to register at local police stations.

The sweeping controls have reinforced perceptions that the government wants to head off even legitimate protests.

"Some security measures are understandable. Look at the United States after the 9/11 terrorist incidents," said Xu Youyu, a retired philosophy lecturer and frequently outspoken critic of government policies.

"But the system in China doesn't have to give the same considerations to civil liberties. The government is strengthening control and supervision over people who have no intention of disrupting the Olympics. This is a violation of basic human rights and undermines the promises made when bidding for the Olympics," Xu said. "This is intolerable."

With the city feeling emptier and less lively, those left feel part of an elaborately staged event meant to show a perfect but unreal Beijing to the half-million athletes, journalists, dignitaries and tourists expected to come to the games.

"It's not about having people enjoy the Olympics. If nobody came that would be a successful Olympics," said Anne Stevenson-Yang, an American private equity consultant in Beijing. "It's theater. The foreigners are there as props but the fewer the better."