Protesters in the Ukrainian capital claimed full control of the city today following the signing of a Western-brokered peace deal aimed at ending the nation's three-month political crisis.

The nation's embattled president reportedly fled the capital for his support base in Ukraine's Russia-leaning east. He was reportedly still in the country.

The Opposition said it had control of presidential administration buildings in Kiev.

"He's not here, none of his officials or anyone linked directly to the administration are here," Ostap Kryvdyk, a protest leader, told a Reuters reporter inside the grounds of the administration building.

He said protesters had not used force to enter the compound.

Media outlets reported that President Viktor Yanukovych left Kiev for his native eastern Ukraine after surrendering much of his powers and agreeing to early elections this fall.

The changes came as part of yesterday's deal intended to end violence that killed scores and left hundreds wounded in Kiev this week as snipers opened fire on protesters.

Andriy Parubiy, a leader of the protest camp on Independence Square, known as the Maidan, was quoted by the Interfax news agency as saying that Mr Yanukovych fled for Kharkiv, the centre of Ukraine's industrial heartland.

The claims of the president's departure could not be immediately confirmed, however.

Mr Parubiy also said today that protesters are now in full control of the capital. Police yesterday retreated from their positions in Kiev's government district, and the night passed quietly.

Despite significant concessions made by Mr Yanukovych, many of the protesters have remained dissatisfied with the deal and pushed for him to be ousted immediately.

They booed opposition figures who took to a stage last night to present the deal, which cuts Mr Yanukovych's powers and calls for early elections but falls short of demands for his immediate resignation.

"Death to the criminal!" some chanted, referring to Mr Yanukovych.

The leader of a major radical group that spearheaded clashes with police, Pravy Sektor, declared yesterday that "the national revolution will continue".

A motion seeking the president's impeachment was submitted late yesterday to the Ukrainian parliament, where members of his faction defected in droves to the opposition side, quickly passing constitutional amendments that trimmed Mr Yanukovych's powers.

It was not clear if and when the impeachment motion would be put to vote.

Neither side won all the points it sought in yesterday's deal, and some vague conditions could ignite strong disputes down the road.

The agreement calls for presidential elections to be moved up from March 2015 to no later than December, but many protesters said that is far too late.

And it does not address the issue that triggered the protests in November - Mr Yanukovych's abandonment of closer ties with the EU in favour of a bailout deal with long-time ruler Russia.

The stand-off between the government and protesters escalated this week, as demonstrators clashed with police and snipers opened fire in the worst violence the country has seen since the breakup of the Soviet Union a quarter of a century ago.

The health ministry put the death toll at 77 and some opposition figures said it is even higher.

The US, Russia and the 28-nation EU are deeply concerned about the future of Ukraine, a divided nation of 46 million.

The country's western regions want to be closer to the EU and have rejected Mr Yanukovych's authority in many cities, while eastern Ukraine that accounts for the bulk of the nation's economic output favours closer ties with Russia.

The parliament yesterday quickly approved a measure that could free Mr Yanukovych's arch-rival Yulia Tymoshenko, who has served two and a half years on a conviction of abuse of office, charges that domestic and Western critics have denounced as a political vendetta.

Legislators voted to decriminalise the count under which she was imprisoned, meaning that she is no longer guilty of a criminal offence.

However, Mr Yanukovych must still sign that bill into law, and then Ms Tymoshenko's lawyers would have to ask the court for her release from prison in Kharkiv, the city controlled by Mr Yanukovych's loyalists where the opposition has little public following.

The deal was a result of two days and all-night of shuttle diplomacy by diplomats from Germany, France and Poland, who talked with the president and the opposition.

In Washington, White House press secretary Jay Carney said the deal is consistent with what the Obama administration was advocating, and that the US will closely monitor whether it is fulfilled, holding out the threat of more sanctions if it's not.

In Moscow, a senior Russian politician criticised the deal as a Western attempt to wrest Ukraine out of Russia's sphere of influence.

Leonid Slutsky, who chairs the committee in charge of relations with other ex-Soviet nations, told reporters that the agreement is "entirely in the interests of the United States and other powers, who want to split Ukraine from Russia".

Russia's mediator Vladimir Lukin refused to sign the deal yesterday, and the Russian foreign ministry warned that Ukraine should take into account all regions in its political transition, apparently referring to the areas in Ukraine's east and south.