Three dark-skinned people have been killed in four days in an apparent outbreak of hate crimes, prompting Moscow police to beef up their presence on the streets and Mayor Yury Luzhkov to appeal for calm.

Police found the body of a 34-year-old native of Kabardino-Balkaria in northwestern Moscow late Sunday, Interfax reported. It was unclear how the unidentified man died. A mobile phone and a wallet with 40,000 rubles were found in his jacket, suggesting that the motive for the attack was not robbery.

On Saturday, 10 young people armed with knives attacked two Kyrgyz natives near the Tekstilshchiki metro station in southeastern Moscow, Interfax said. Merlan Eygeshov, 25, died after being stabbed 11 times, while the other, Abdametal Mamydov, 21, was hospitalized and in critical condition, the report said.

A Tajik citizen was stabbed to death and a teenage boy was knifed in separate attacks late Thursday.

The Kyrgyz Interior Ministry lodged a complaint Monday about the violence, saying six Kyrgyz citizens have been killed in Russia since Jan. 1.

City authorities said they were responding.

"We are not talking about specific districts, but rather about a general boost in the number of police officers across the city," a city police spokeswoman said on condition of anonymity.

The spokeswoman was unable to provide details, saying only that officers are being expected to patrol more of the city and work longer hours.

National media reported that police were focusing their efforts on southeastern Moscow, where attacks have been the most frequent. The spokeswoman said, however, that no district was being afforded special attention.

Calls to the Kyrgyz Embassy for comment went unanswered Monday.

Luzhkov, meanwhile, held a meeting Monday with the Moscow representatives of Central Asian countries whose citizens have been attacked with increasing frequency. The results of the meeting were not immediately available.

Despite a slight dip in the number of murders in Moscow in 2007, a year-on-year analysis reveals racially motivated killings make up a growing percentage, according to statistics from the Sova Center, which tracks hate crimes.

Sova recorded six racially motivated killings in January.

Police recorded 1,018 murders in 2005. The Sova Center said 16 of those, or 1.57 percent, were racially motivated. A year later, the figure more than doubled to 37 of 1,191 (3.11 percent) total murders. Last year, 42 of 1,101 killings (3.8 percent) were racially motivated.

Alexander Verkhovsky, Sova's director, dismissed the police's promise to address the issue as a cyclical phenomenon that appears whenever the media have little else to report.

"Police officials always try and play down the role of racism in these crimes, though prosecutors are starting to admit what's really going on," he said.

In an interview with Komsomolskaya Pravda published Monday, Moscow police chief Vladimir Pronin said "there is no organized skinhead movement" in Moscow, referring to ultranationalists typically suspected of attacks on dark-skinned people.

"But there are separate groups," he said.