* Law would ban setting up tents, wearing face masks
* Ukraine protests continue despite turn-of-year lull
* Move certain to fuel opposition fears of imminent crackdown
KIEV, Jan 16 (Reuters) - Supporters of Ukrainian President Viktor Yanukovich rammed a sweeping law through parliament on Thursday in an attempt to curb anti-government protests, sparking an outcry from the opposition and raising tensions on the streets.
The law, backed by 235 of 450 lawmakers, said unauthorized installation of tents, stages or amplifiers in public places in Ukraine would be punished by a fine of up to $640 or by up to 15 days in detention.
People and organisations who provided facilities or equipment for unauthorized meetings would be liable to a fine of up $1,275 or by detention of up to 10 days.
Yanukovich's refusal in November to sign a free trade deal with the European Union in favour of boosting ties with Ukraine's former Soviet master Russia brought hundreds of thousands of Ukrainians out on to the streets in protest.
Though numbers have dwindled since, several hundred people remain camped out on the central square of the capital Kiev or in public buildings in adjoining streets, despite a New Year and Orthodox Christmas lull.
Opposition politicians regularly use a stage in the square to broadcast messages of support to the protesters and the law, assuming it is signed into force by Yanukovich, would clearly make such action illegal.
The decision in parliament, taken suddenly by a show of hands which caught the opposition off-guard, followed a court ban on protests in Kiev, boosting opposition fears of an imminent police crackdown.
"What happened today in parliament is a violation of laws," said boxer-turned-politician Vitaly Klitschko, an opposition leader who is regarded as a strong challenger to Yanukovich for the presidency. "They do not have any legal basis," he said.
And far-right nationalist Oleh Tyahnibok, another opposition leader, said the vote was "simply a usurping of power".
The law would make it an offence punishable by up to 15 days detention to wear a mask or face-covering like that adopted by many of the protesters, particularly those from the nationalist parties.
Dissemination of extremist information and slander was also banned and seemed to be aimed at forcing the removal of political graffiti on walls and bill-boards, pillorying Yanukovich and his government.
The move was certain to fuel opposition suspicions that riot police would soon crack down to end two months of protests. These have widened into rallies, sometimes involving thousands of people at the weekend, against sleaze and corruption in power.
The EU's ambassador to Ukraine, Jan Tombinsky, joined opposition leaders in condemning the way the law was rushed through parliament by a show of hands rather than by the customary electronic system of voting - a mechanism which opposition deputies can physically block.
"I am concerned about the way some laws were voted in parliament today. Norms should be adopted through proper procedures, otherwise the credibility of democratic institutions and of the legal system is at stake," he said in a statement. (Reporting By Pavel Polityuk; Writing by Richard Balmforth)