Russian lawmakers have approved a bill that makes fines radically higher for people taking part in unauthorized rallies.

The law was passed Tuesday in the third, and final reading with 241 votes for and 147 against in the lower house of parliament.

It raises the maximum fine for illegal street protest from about $30 to about $9,000, introduces the option of compulsory community service of up to 200 hours and makes other changes aimed at hampering unsanctioned protests.

Earlier Tuesday police detained some 20 people outside the parliament building who were protesting the bill, introduced by the ruling United Russia party.

The party, led by President Vladimir Putin, originally proposed an increase to at least $31,000.

The Kremlin-controlled parliament has begun debating amendments to the bill. Opposition lawmakers have proposed more than 350 amendments in an effort to delay implementation of the measure which still needs passage by the upper house and a signature by Mr. Putin.

The bill was introduced after activists held mass protests against the possible 12-year rule of Russian President Vladimir Putin, a scenario that many Russians find unsettling.

Critics say it will increase tensions in Russian society and make it very difficult to hold protests.

Earlier this year, Mr. Putin won a controversial third term as Russia's president despite huge opposition protests preceding the March election.