Russian internet users and the media have warned of a new online "iron curtain" brought about by tough new controls critics say will stifle dissent.

Key points: If the laws are passed, Internet traffic will be controlled by the state

If the laws are passed, Internet traffic will be controlled by the state Russian authorities say it is part of a drive to increase sovereignty

Russian authorities say it is part of a drive to increase sovereignty Some search results are already censored in Russia

The anger has been growing in recent weeks, and in the latest protests, thousands of people took to the streets of Moscow and two other cities to rally against the proposed changes.

Politicians last month backed the tighter internet controls contained in legislation they say is necessary to prevent foreign meddling in Russia's affairs.

People gathered in a cordoned off Prospekt Sakharova street in Moscow, made speeches on a stage and chanted slogans such as "hands off the internet" and "no to isolation, stop breaking the Russian internet".

"I attend this rally to show our Government that I am not ready to renounce [the] internet, anonymity and the right to express my opinion," one protester said.

Moscow police put the numbers at 6,500 but there were some estimates that put the number higher than 15,000 protesters.

Opposition activists said on Twitter that police had detained 15 people at the Moscow rally, confiscating their banners and balloons. Police have not announced any detentions.

The protests in Moscow, the southern city of Voronezh, and Khabarovsk in the far east had all been officially authorised. A handful of activists in St Petersburg took to the streets without the authorities' consent.

In recent years, Russia has already blocked access to certain websites and messaging services. ( Reuters: Shamil Zhumatov )

Russia has in recent years attempted to curb internet freedoms by blocking access to certain websites and messaging services such as Telegram.

February's bill passed in the Russian parliament on the first reading out of three.

It seeks to route Russian web traffic and data through points controlled by the state and proposes building a national domain name system to allow the internet to continue functioning even if the country is cut off from foreign infrastructure.

The second reading is planned this month and, if passed, the bill will need to be signed by the Upper House of the Parliament and then by President Vladimir Putin.

The legislation is part of a drive by officials to increase Russian "sovereignty" over its internet segment.

Russia has introduced tougher internet laws in recent years, requiring search engines to delete some search results, messaging services to share encryption keys with security services and social networks to store Russian users' personal data on servers within the country.

Reuters