Russian authorities for the first time blocked nationalists from using a popular Internet blog to organise anti-migrant demonstrations, one of the leaders of a nationalist group told Reuters on Wednesday.
In January President Vladimir Putin ordered the security services to stamp out growing extremism and racism partly fuelled by envy towards successful businesses run by Caucasians and Central Asians and two wars in Chechnya from 1994.
Authorities monitoring the livejournal web site made it hard to organise protests on Tuesday against Chechens in the southern city of Stavropol, Alexei Mikhailov, one of the leaders of Action Against Illegal Immigrants (DPNI), told Reuters by telephone.
"I think we should organise a protest but in Stavropol everything is under police control," he said.
In a fight between Russians and Chechens on May 24 in Stavropol, a city of 350,000 bordering Chechnya, a Chechen man died. Ten days later unknown attackers killed two Russians in what many think was a revenge attack.
On Tuesday hundreds of angry Russians gathered in the city's main square after the Russians' funerals.
In September Chechens fled the northwestern town of Kondopoga after Russian rioters avenged two murders by torching their businesses, homes and cars.
DPNI, which says it is against violence, has organised marches in Moscow and helped the demonstrators in Kondopoga.
Media said Stavropol had all the hallmarks of another Kondopoga. But in Stavropol the police were organised and DPNI were missing.
"It's a southern region with more immigrants and relations are more tense and more explosive than Kondopoga," Mikhailov said.
Police detained 50 protesters at the rally and Mikhailov said police held another of DPNI's leaders for nine hours when he arrived in the city, preventing him from reaching a meeting.
Crucially, Mikhailov said, the authorities had extended their watch to the Internet and any blog on livejournal containing DPNI failed to be posted.
"It is a significant part of our work and the most politically active people read livejournal and write there," Mikhailov said. "This group is a priority group."
Russian interior minister Rashid Nurgaliev said police tactics had been a deliberate ploy to defuse potential trouble.
"The situation is under control and will not develop like we saw in Kondopoga," the newsru.com website reported Nurgaliev as saying.
On Wednesday Russian television showed police patrolling Stavropol which was quiet although people said it was still tense.
(Additional reporting by Vera Kalian)