Russia's players and their families are under police protection after their World Cup failure, according to a media report.
The wife of Russia goalkeeper Ruslan Nigmatullin told the Sovietsky Sport newspaper that their Moscow apartment had been put under surveillance by plain-clothed police.
The newspaper quoted Yelena Nigmatullina as saying that shewas happy with the measures. Other players were quoted as saying police had taken their home addresses on their return to ensure their safety.
A senior official with the Russian Football Union said on Monday that he was aware of the report.
"Even if the secret service has been empowered to protect the players, no one will comment on it because that's the nature of the police work," Sergei Kulikov said.
"The media has also blown it a bit out of proportion. There may have been a few angry phone calls with threats to players from some extremist groups, but those were isolated incidents."
The Russians returned home last week to widespread scorn from the country's media and fans. Coach Oleg Romantsev and his staff resigned after the tournament.
After beating Tunisia 2-0, Russia lost 1-0 to Japan and 3-2 to Belgium, failing to advance from what was regarded as one of the easiest first-round groups.
Thousands of angry drunken fans went on the rampage in the centre of Moscow on June 9 following Russia's defeat by Japan, leaving one dead and more than 100 injured. Riot police sealed off Moscow's Vnukovo airport to prevent any repeat when the team arrived home.
