Yanukovych Accuses Opposition of Increasing Tensions in Ukraine

President Viktor Yanukovych on Thursday savaged the opposition for inflaming tensions in Ukraine's protest crisis after he unexpectedly went on sick leave with no end in sight to the turmoil.

In an address to the nation, Yanukovych turned on the "irresponsible" opposition which has refused to abandon over two months of protests despite a string of concessions, including an amnesty for jailed demonstrators.

The street rallies first erupted when the president backed out of a key pact with the European Union in November in favor of closer ties with Moscow, but the unrest has since spiraled into wider anti-governments protests that have led to the cabinet's resignation.

The opposition has insisted that only the removal of the president will satisfy the hundreds of thousands of protesters who have braved freezing temperatures to voice their anger in recent weeks.

In the latest twist to the saga, Yanukovych's office on Thursday announced the leader had fallen ill with an "acute respiratory infection".

The president's sick leave -- which comes as many Kiev protesters have themselves been taken ill in temperatures as low as minus 20 degrees Celsius (-4 degrees Fahrenheit) -- could well buy Yanukovych some time in the increasingly fraught negotiations to end the turmoil.

The crisis gripping Ukraine has turned into the former Soviet state's biggest challenge since independence in 1991.

The upheaval has also reverberated on the international stage, with Russian President Vladimir Putin urging the European Union not to meddle but Western states under pressure to consider sanctions against Ukrainian officials.

Ukraine's first post-independence president Leonid Kravchuk on Wednesday warned that the country was "on the brink of civil war".

Thousands of protesters were on Thursday still occupying much of Kiev's city center, including radical activists in balaclavas who patrolled the barricades carrying crowbars.

Hours after his sick leave was announced, Yanukovych issued a defiant statement accusing the opposition of behaving irresponsibly by not calling off the protests.

"The opposition is continuing to inflame the situation and is calling on people to stand in the freezing cold due to the political ambitions of several leaders," he said.

He said the opposition was making "ill-considered and irresponsible announcements, thinking about their own ratings more than the life and health of people."

But in a rare show of contrition, Yanukovych also admitted he needed to take more account of the country's mood.

"From my side, I will show more understanding for the demands and ambitions of people, taking into account the mistakes that authorities always make."

Yanukovych has already granted several concessions to the protesters, including accepting the resignations of Prime Minister Mykola Azarov and the entire cabinet, as well as allowing the annulment of tough anti-protest laws.

And late on Wednesday Ukraine's parliament, with backing from the ruling Regions Party, passed a bill that would amnesty arrested protesters.

Bu the opposition did not take part in the vote because the amnesty is conditional on protesters leaving occupied streets and buildings 15 days after it comes into force.

According to prosecutors, 234 people have been arrested across Ukraine in the protests. The amnesty would apply to all save those accused of grave crimes.

One of the opposition leaders, Svoboda (Freedom) party leader Oleg Tyagnybok, said that parliament had essentially adopted a law about "hostages" as those arrested during the crisis would now be held until the occupied buildings are vacated.

The UDAR (Punch) party leader and world boxing champion Vitali Klitschko, another opposition leader, warned: "Instead of lowering the temperature in society, this is going to raise it."

Following complaints from Ukrainian companies, the Russian customs service was on Thursday forced to deny claims that Moscow had introduced tighter border checks, a tried-and-tested method of pressuring Kiev in the past.

The Federation of Employers of Ukraine, a lobby group, said on Wednesday that Russian customs had introduced "rigorous" checks on Ukrainian-made foodstuffs, machinery, metals and trading equipment.

Ukraine remains mired in deep economic trouble and has accepted a $15-billion bailout from Moscow, though Russia this week warned that further payments will only be released when a new government is named.

Ukraine saw zero growth last year after nine months of economic declines were followed by a strong fourth quarter, the statistics committee said on Thursday.