Russia Steps Up Raids Against Migrants Sergey Ponomarev for The New York Times Hundreds of Vietnamese were among those rounded up in Russia and sent to a temporary detention camp in Moscow. MOSCOW - It all began with the arrest of a rape suspect in an open-air market two weeks ago. A brawl erupted. A police officer was injured. It was a minor, if ugly, episode that might quickly have been forgotten except that it snowballed into a sweeping government campaign - not against crime in the city's markets, but against illegal immigrants, though the suspect was not an immigrant at all. In the days that followed, the police and migration officials mounted raids at markets across Moscow, in factories that operated in the shadows of the law, in the city's subway system and on the streets. At last count nearly 1,500 foreigners had been detained, according to the Federal Migration Service. That number included 586 people, most of them Vietnamese, who were being held in a temporary tent camp more appropriate for a war zone or the scene of a natural disaster than the center of a capital city. "This is absolutely normal," Moscow's mayor, Sergei S. Sobyanin, told the newspaper Vedomosti last week, defending the government's actions. In any society, in any country, if an emergency situation happens, then the government and society begin to act more harshly. The campaign - cheered, for the most part, by the news media and the public here - has exposed the complexity and corruption of Russia's labor market and tapped into the country's ever-simmering ethnic animosity. And that has raised concerns among foreign embassies and provoked outrage from national and international human rights groups. Svetlana A. Gannushkina, the director of the refugee-rights group Civil Assistance, denounced the camp as "an illegal place of detention" that had ensnared innocent people, even those with permission to live and work in Moscow. The Vietnamese Embassy sent its diplomats to the camp on Friday - a week after it first opened - to try to resolve the matter and begin to identify those being held. Many did not have their passports when the police raided a shadowy textile factory near where the tent camp appeared, and speak little Russian. Human Rights Watch on Friday called conditions in the camp inhuman and demanded that the authorities close it and end a campaign it said was aimed at people based on the color of their skin, not their nationality. Those being held include people from former Soviet republics with close ties to Russia, like Uzbekistan, Kyrgyzstan and Tajikistan, as well as Syria, Afghanistan and Egypt. "Everything about this massive sweep violates Russia's obligations under international law," Human Rights Watch's director in Russia, Tanya Lokshina, said in a statement. Prolonged detention without counsel, ethnic profiling, inhuman conditions - it should stop now. There is little evidence that it will end soon. The first 31 of the Vietnamese workers were deported over the weekend. The head of the Vietnamese Embassy's consular division, Lee Hong Chung, said in a written response to questions about the detentions that the embassy was working closely with the Russian authorities to resolve the fate of the others. The raids, which some critics have called "zachistki," a word for cleansing operations that gained currency during Russia's war in Chechnya, continue almost daily, supported by a large majority of Russians, nearly two-thirds of whom think immigrants increase crime and corruption, according to the results of a recent poll. Not surprisingly perhaps, the scourge of illegal immigration has been taken up not only by Mr. Sobyanin, but also by his challengers across the political spectrum in the mayoral election to be held on Sept. The most prominent challenger is Aleksei A. Navalny, the anticorruption activist and champion of a more democratic political system, whose remarks have unnerved more liberal members of the political opposition. He has frequently stated that half of all violent crimes are committed by immigrants, a figure that is disputed. "For me this isn't just a number," Mr. Navalny said in a recent stump speech. For me it means one simple thing: that the women in my building are afraid to go out on the street at night. Noah Sneider contributed reporting.