Russia's media watchdog Roskomnadzor on Friday effectively banned the use of several major VPN networks, including the widely used Nord VPN and Express VPN. 

The move comes as authorities ramp up control of the Russian segment of the internet, blocking access to dozens of opposition-linked websites ahead of a parliamentary election this month. 

The watchdog said in a statement that the services violated Russian law by allowing access to illegal online content. 

Four other VPN providers were also banned. 

Roskomnadzor said allowing access to blocked content "created conditions for illegal activities, including those related to the distribution of drugs, child pornography, extremism and suicidal tendencies".

Roskomnadzor increased pressure on Western tech giants Google and Apple for their refusal to remove an app developed by the team of jailed Kremlin critic Alexei Navalny. 

The Russian government in recent years has been tightening control over the internet under the pretext of fighting extremism and protecting minors and has begun developing a so-called "sovereign internet".

Kremlin critics denounce official oversight of the web as a way to silence dissent.

Parliamentary elections are scheduled for later this month, with nearly all vocal Kremlin critics including Navalny's allies barred from running.