Russia should not intervene in the Ukraine crisis, Britain's Foreign Secretary William Hague said Sunday, insisting it would not be in Moscow's interests to weigh in.

Speaking after Ukraine's parliament ousted President Viktor Yanukoych following a bloody end to three months of protests, Hague said there was a "moment of opportunity" for Ukraine but there were still "many dangers" ahead.

The White House welcomed the release from prison on Saturday of former Ukraine prime minister and opposition leader Yulia Tymoshenko, saying that the strife-hit country's people "must determine their own future."

"We wish her a speedy recovery as she seeks the appropriate medical treatment that she has long needed and sought," a statement said, adding: "The unshakeable principle guiding events must be that the people of Ukraine determine their own future."

A vast country estate, marble-lined mansions, a private golf course and zoo: the unimaginable luxury of the private residence of departed Ukrainian President Viktor Yanukovych flung open for all to see.

As parliament voted to oust Yanukovych Saturday and he fled to a pro-Russian bastion in east Ukraine after months of bloody protest again his rule, thousands of Ukrainians wondered awestruck around the breathtaking luxury of his abandoned property some 15 kilometers (10 miles) from Kiev after it was taken by demonstrators.

European Commission President Jose Manuel Barroso on Saturday welcomed the release of Ukraine's jailed pro-Western opposition icon Yulia Tymoshenko and called for an independent legal system in the troubled country.

"Welcome release of Tymoshenko. Independent justice system essential for a democratic Ukraine," Barroso said on his Twitter account.

The dramatic events in Kiev on Saturday do not amount to a coup, Polish Foreign Minister Radoslaw Sikorski said, after the Ukrainian president accused the emboldened opposition of a coup d'etat as it asserted control in the capital.

"No coup in Kiev. (Government) buildings got abandoned," Sikorski tweeted, adding that Ukrainian President Viktor Yanukovych has 24 hours to sign into law constitutional reforms agreed under a peace deal on Friday, which Poland helped broker.

Russia's foreign ministry on Saturday warned that "extremists" in Ukraine posed a threat to the country's sovereignty, after embattled President Viktor Yanukovych accused the emboldened opposition of staging a "coup".

"The opposition has not only failed to meet a single one of its obligations, but is also pushing new demands, submitting itself to armed extremists and looters whose actions pose a direct threat to the sovereignty and constitutional order of Ukraine," the ministry said in a statement.

Germany and France on Saturday urged the Ukrainian government and the opposition to respect a peace deal agreed a day earlier to end the ex-Soviet country's worst crisis since independence.

"It is now up to the two sides in the conflict -- the government as well as the opposition -- to stick to what was agreed and to begin building a relationship of trust," German Foreign Minister Frank-Walter Steinmeier said in a statement, as the regime of President Viktor Yanukovych appeared close to collapse after months of protests.

Protesters in Ukraine seized control of the capital Kiev and hailed freed opposition leader Yulia Tymoshenko in a historic turn of events Saturday, but marginalized President Viktor Yanukovych defiantly declared he still wielded power.

The situation in the ex-Soviet nation -- deeply divided between aspirations towards the European Union and loyalty to Russia -- was still fluid and uncertainty reigned over whether the opposition had definitively triumphed over Yanukovych on a day of high drama exactly three months into the country's crisis.

Militant anti-government activists in Ukraine on Saturday threatened to storm the president's palace and shatter a fragile peace deal to end the ex-Soviet country's bloodiest crisis since independence.

Embattled President Viktor Yanukovych signed a deal Friday with the opposition paving the way for early elections and forming a unity government while granting amnesty for protesters detained during three days of unrest that claimed nearly 100 lives.

Poland's foreign minister said Friday he had received signals in Kiev that the Ukrainian president was prepared to use force should the opposition have rejected an EU brokered roadmap to end a bloody crisis.

"We were getting signals that in case the agreement fails, President (Viktor) Yanukovych was preparing to use Interior Ministry forces," Foreign Minister Radoslaw Sikorski told reporters in Warsaw Friday evening after returning from Kiev.