* Opposition says Yanukovich yields nothing in talks
* Protesters occupy ministry building, light fires
* Klitschko says he fears more bloodshed (Adds details)
By Richard Balmforth and Pavel Polityuk
KIEV, Jan 24 (Reuters) - Ukrainian protesters erected more street barricades and occupied a government ministry building on Friday after the failure of crisis talks with President Viktor Yanukovich, pointing to a further hot weekend of protest.
Yanukovich's Party of the Regions confirmed reports that two months of anti-government protests were spreading to other parts of the country, particularly the west, where "extremists" had seized regional administration buildings.
"The situation has grown sharper throughout the country," the party said in a statement in which it called on people to disregard the calls of "radical troublemakers" to turn out for protest rallies.
Opposition leader Vitaly Klitschko, who with two other opposition leaders failed to wring any concessions from Yanukovich late last night, said the only way out of the impasse lay with international mediation.
"Any discussion of how to settle the crisis in Ukraine must take place with the involvement of the international mediators of the highest level," a statement from his Udar party quoted him as saying.
"Instead of shifting to solving the situation by common sense, Yanukovich has declared war on his own people. He is trying to hold on to power at the price of blood and de-stabilisation of the situation in the country. He has to be stopped," the boxer-turned-politician said.
After news emerged on Thursday night that talks had been fruitless, about 1,000 demonstrators moved away from Kiev's Independence Square in the early hours of Friday and began to erect new barricades closer to presidential headquarters.
Masked protesters, some carrying riot police shields seized as trophies, stood guard as others piled up sandbags packed with frozen snow to form new ramparts across the road leading down into the square.
A group of protesters took control of the main agricultural ministry building in the centre. "We need the place for our people to warm up," a local protest leader was quoted as saying by Interfax news agency.
Opposition leader Vitaly Klitschko, after leaving a second round of talks with Yanukovich empty handed, late on Thursday voiced fears the impasse could now lead to further bloodshed.
At least three protesters have been killed so far - two from gunshot wounds - after clashes between protesters led by a hard core of radicals and riot police.
But though radical protesters lit some tyres at the main flashpoint area near Dynamo Kiev football stadium, they appeared to have heeded a call from the opposition to maintain a truce.
Three opposition politicians - Klitschko, former economy minister Arseny Yatsenyuk and far-right nationalist Oleh Tyahnibok - had tried to wring concessions from Yanukovich that would end two months of street protests against his rule.
In action away from Kiev, thousands stormed regional administration headquarters in Rivne in western Ukraine on Thursday, breaking down doors and demanding the release of people detained in the unrest there, UNIAN news agency reported.
In the town of Cherkasy, 200 km (125 miles) south of Kiev, about 1,000 protesters took over the first two floors of the main administration building and lit fires outside the building.
Similar action took place in Lviv, Ternopil, Ivano-Frankivsk and Khmelnytsky in western and central Ukraine, as well as parts of the northeast, the Party of the Regions said.
More than 100 people have been detained in the unrest, including 24 formally arrested, according to police.
In Kiev, scores of people have been hurt on both sides, with many losing eyes from projectiles and police rubber bullets.
Hundreds of thousands took to the streets in the capital after Yanukovich backed away from signing a free trade deal with the European Union, which many people saw as the key to a European future, in favour of financial aid from Ukraine's old Soviet master Russia.
But the movement has since widened into broader protests against perceived misrule and corruption in the Yanukovich leadership.
Protesters have been enraged too by sweeping anti-protest legislation that was rammed through parliament last week by Yanukovich loyalists in the assembly.
Earlier on Thursday, Yanukovich had suggested he might be prepared to make concessions to the opposition when he called for a special session of parliament next week to consider the opposition demands and find a way out of the crisis.
But this did not impress opposition leaders.
Underlining the level of mistrust between the government and opposition, Prime Minister Mykola Azarov on Thursday accused protesters of trying to stage a coup d'etat and dismissed the possibility of an early presidential election to resolve the standoff.
Yanukovich officials have however said they see no need to declare a state of emergency.
U.S. Vice President Joe Biden phoned Yanukovich on Thursday and warned him that failing to de-escalate the standoff could have "consequences", the White House said.
German Chancellor Angela Merkel expressed anger over the way laws had been rammed through calling into question basic freedoms, while French President Francois Hollande called on Ukrainian authorities to "rapidly seek dialogue". (Editing by Andrew Roche)