Moscow, Feb 5 (IANS): The detention of protesters at the recent "illegitimate rallies" in Russia is a police measure against law violators, not an act of repression, Kremlin Spokesman Dmitry Peskov said.

The ongoing protests first broke out across Russia on January 23 when thousands of people took to the streets against the detention of opposition figure and Kremlin critic, Alexei Navalny.

Addressing a daily briefing on Thursday, Peskov said that claims of repression were emotionally charged, and added that there were multiple direct assaults on police officers during these demonstrations in support of Navalny.

While overcrowded detention centres are under pressure, all possible measures are currently being taken to tackle paperwork problems, he said.

Peskov also slammed a US Congress bill on sanctions against Russia over the Navalny case.

"We consider such approaches in bilateral relations unacceptable," the spokesman said.

A Moscow court on Tuesday ruled to replace a suspended sentence in 2014 for Navalny with three and a half years in jail due to his breaches of probation conditions by failing to show up for regular checks.

The Kremlin critic was detained on January 17 upon his landing at a Moscow airport from Germany, where he had received medical treatment for alleged poisoning over the past few months.

Navalny's detention sparked the mass protests in major Russian cities, including capital Moscow, St Petersburg, Novosibirsk, Yakutsk, Omsk and Yekaterinburg, during the past two weekends as his supporters took to the streets demanding his release.

Western countries have also pressured Moscow to free him.