Chinese authorities are anxious to project a perfect image of Beijing this week for the 16th Communist Party Congress. Because of tight security, there have been few visible protests. But thousands of people from all parts of the country have quietly converged on the capital, hoping to have their grievances heard.

Mr. Zhao has traveled some 1,500 kilometers from his village on China's border with Russia, to be in Beijing for the party congress. Mr. Zhao, a 45-year-old, unemployed father of two, does not wish to reveal his full name. He says he made his journey here with four other villagers living near the border town Heihe, in Heilongjiang Province. He says all of them are victims of police abuse.

Mr. Zhao says his case dates back three years, when his nine-year-old nephew was hit and killed by a van. He says police collected evidence and said the driver was at fault. But he says soon after the original investigation was closed, the police reversed their conclusion and said the child had jumped onto the van, then fell off.

Mr. Zhao thinks someone bribed the police to change the verdict and hide the evidence, so he filed a lawsuit against the local security bureau to obtain compensation for his nephew's death, and an apology. Instead, Mr. Zhao found his family exposed to death threats and harassment. Sometimes men came to his house late at night, he says, and threw rocks at his windows, warning him to drop the case.

Mr. Zhao says in China, those in power are above the law and can do whatever they want. He says the only people who can monitor Communist Party officials are other party officials. So after losing faith in the local courts, Mr. Zhao and his fellow villagers are appealing to authorities in Beijing for justice.

Mr. Zhao is just one of thousands of ordinary Chinese who see the party congress, which is held once every five years, as a chance to bring their grievances before the country's top leaders.

Dominique Muller, a researcher with Amnesty International in Hong Kong, says people from all sectors of society believe appealing to Beijing is their last hope after exhausting the meager legal system. But Ms. Muller says most of these people only end up caught in a massive security net that falls over Beijing during the congress. "In China, there's actually a long tradition of petitioning the authorities, and obviously sometimes it works, but in the majority of cases it doesn't," she says. "And I think at a time like this, when security is so tight, they may actually face harsher repression."

Police in Beijing began cracking down on potential troublemakers before the congress opened last Friday.

Pro-democracy activists have been detained. Rights groups say a leading member of China's underground Christian church and his wife have been taken from their home in Beijing to the northern province Shanxi. But Ms. Muller says most of those the police target do not directly challenge the government. They are seen merely as a blemish on the face Beijing wishes to present to the world. "Many ordinary citizens are picked up, people without official permits or maybe people with special permits to stay in Beijing, are actually picked up, sent back to their home provinces," she says. "Some are detained under administrative detention and then sent back."

Ms. Muller says police have set up checkpoints on major highways leading into Beijing, and security has been stepped up on trains heading to the capital. She adds that hotels in the city have been ordered not to rent rooms to ethnic Muslim Uighurs from western China.

Mr. Zhao, of Heilongjiang, too, has caught the attention of the authorities. He says that his local government sent representatives to Beijing before the party congress began, to look for people from their district who might cause trouble. He says a Heilongjiang official found him in Beijing, and warned him to return home voluntarily or go by force. Mr. Zhao says he already managed to meet someone at the public prosecutor's office in Beijing, so he decided to head back north again.

But Mr. Zhao doubts that his family will receive compensation for the death of his nephew. "We have already suffered so much the last three years," he says, "we have nothing more to lose." Mr. Zhao says that if the case is not resolved he will be back in Beijing again, "but next time I may demonstrate at Tiananmen Square."