* Opposition seeks to keep up pressure after Sunday's clashes
* Protesters still confronting police on Kiev streets
* EU ministers denounce "anti-democratic' legislation in Ukraine (Adds Yanukovich comments, EU discussions)
By Richard Balmforth
KIEV, Jan 20 (Reuters) - President Viktor Yanukovich, reeling from the worst violence for decades in the Ukrainian capital, appealed for compromise on Monday as police and demonstrators clashed again in the streets.
Yanukovich is battling to reassert his authority after scores of people were injured in Kiev on Sunday in pitched battles between protesters and police that could seriously hurt his chances of re-election next year.
With tension still high, about 1,000 protesters confronted police on Monday near Kiev's main government headquarters. Scores of mainly young people hurled projectiles at police throughout the day and ignored appeals to disperse.
After weeks of mass protests over Yanukovich's decision to shun a trade pact with the European Union and turn instead towards Russia, demonstrators have been further enraged by sweeping laws rammed through parliament to curb public protest,
"I ask you not to join those who seek violence, who are trying to create a division between the state and society and who want to hurl the Ukrainian people into a pit of mass disorder," Yanukovich said in an appeal on his website.
He called for "dialogue and compromise" to end the unrest. But he made no mention of possible concessions, nor did he refer to peace talks with the opposition which were to have got under way on Monday.
The opposition warned him not to use these as an effort to buy time, while boxer-turned politician Vitaly Klitschko, one of its leaders, insisted he wanted Yanukovich to take part personally in the talks. As of Monday evening it was unclear if and when talks would take place.
The violence, the worst civil unrest anyone could remember in post-war Kiev, stemmed from a rally on Sunday attended by more than 100,000 people in defiance of a court ban.
Despite opposition calls for only peaceful action, the rally descended into violence when masked youths broke away and tried to march on parliament before being stopped by police.
In the ensuing clashes, more than 60 police were injured, with 40 being taken to hospital, police said. Kiev's medical services said about 100 civilians had sought medical attention.
Streets on Monday were littered with bricks and debris, including burned-out buses and trucks from Sunday's mayhem in which protesters bombarded police with fireworks, flares and later petrol bombs. Police replied with rubber bullets, stun grenades and water cannon.
Seeking to keep the advantage established on the streets, the opposition on Monday warned Yanukovich that he should not try to buy time in the hope protesters would lose heart.
"It's important that these talks have a real result," said Klitschko, who met Yanukovich late on Sunday at his country residence as the clashes raged.
"If the authorities again break their word, the situation will inevitably escalate," he said, adding that the president must be part of any dialogue.
Klitschko, seen as a strong potential contender for the presidency, later urged people outside Kiev to come to the capital to swell the ranks of protesters.
WAVE OF PROTESTS
The protests convulsing the ex-Soviet republic stem from Yanukovich's decision to spurn the EU's free trade deal in favour of closer economic ties with Russia, Ukraine's former Soviet overlord. He has been rewarded by a $15 billion aid package from Moscow including credits and much cheaper gas.
Apart from the violence near the government building, hundreds of protesters remain camped on Kiev's main Independence Square, which has become a platform of resistance to Yanukovich's rule.
The trigger for Sunday's large rally was the passage of new laws which outlaw virtually all anti-government protest and, the opposition says, pave the way for a dictatorship.
The laws ban unauthorised installation of tents, stages or loudspeakers in public and allow heavy jail sentences for participation in "mass disorder". They outlaw dissemination of "extremist" or libellous information about Ukraine's leaders.
In Washington, the White House expressed "deep concern" that criminalising peaceful protests would weaken Ukraine's democratic foundation. It threatened sanctions against Kiev.
Swedish Foreign Minister Carl Bildt said in Brussels: "It is the most solid package of repressive laws that I have seen enacted by a European parliament for decades."
Bildt and his Lithuanian counterpart, Linas Linkevicius, said further violence could lead to EU sanctions against Ukraine, although no official discussions had been held so far.
"Personally, I should say that if something goes wrong, it cannot be ignored. It will not be ignored by EU member states," Linkevicius told Reuters on the sidelines of an EU foreign ministers' meeting.
In practice it might be hard for EU governments to agree on sanctions. Any measures would probably be limited to asset freezes or visa bans against individuals deemed responsible for violence.
Up to now, Yanukovich has refused to yield to any of the opposition's core demands to sack his government and the interior minister over heavy-handed police action against demonstrators in December. (Additional reporting by Pavel Polityuk in Kiev and Adrian Croft in Brussels; Writing By Richard Balmforth; Editing by Mark Trevelyan)