KIEV (AFP) - Pro-Russian activists with clubs and whips clashed with pro-Kiev supporters on Sunday as tens of thousands rallied across Ukraine in rival protests, and Russian President Vladimir Putin dug in his heels in the stand-off with the West.
German Chancellor Angela Merkel delivered a strong rebuke to the Russian strongman, telling him a planned Crimean referendum on joining the Russian Federation was illegal and deploring the lack of progress on creating an international diplomatic group to resolve the crisis.
In phone conversations with Ms Merkel and British Prime Minister David Cameron, Mr Putin in turn accused Ukraine's new leaders of failing to rein in "ultra-nationalist and radical forces".
Defying Western condemnation of the March 16 referendum, he asserted the pro-Russian authorities in Crimea organising the vote were legitimate and acting "based on international law".
But Kiev got crucial backing as United States (US) President Barack Obama invited interim Prime Minister Arseniy Yatsenyuk to the White House on Wednesday to show support.
Ukraine could also sign a political agreement with the European Union (EU) for greater integration on March 17 or 21 - dates on which EU foreign ministers and leaders will meet in Brussels - Ukraine's Foreign Minister Andriy Deshchytsya said in an interview.
Kiev had earlier said it planned to sign the deal before snap presidential elections on May 25.
Speaking at a rally on Sunday, Mr Yatsenyuk vowed that Ukraine would not cede "an inch" of its territory to Moscow, even as Russian forces tightened their grip over Crimea, He told a crowd of thousands of Kiev: "It is our land".
This came as a senior Russian lawmaker said Moscow had set aside US$1.1 billion (S$1.4 billion) in aid for the strategic Black Sea peninsula, now under Russia's de facto control.
Diplomatic talks to solve the worst post-Cold War crisis between Russia and the West have brought little except mutual accusations and grave warnings.
IMPORTANT TO BE UNITED
In Kiev, Mr Putin's top foe Mikhail Khodorkovsky, a former Russian oligarch who spent a decade in Russian prisons, addressed a crowd of thousands on Independence Square, the epicentre of the protests.
"They told me what the authorities did here. They did this with the agreement of the Russian leadership," an emotional Mr Khodorkovsky said in reference to the 100 people killed towards the end of three months of protests against ousted President Viktor Yanukovych.
Thousands of supporters for integration with Russia also seized regional government headquarters in the eastern city of Lugansk and raised a Russian flag on the local security forces' headquarters in Donetsk.
Illustrating the divisions in Ukraine, interim President Oleksandr Turchynov led a minute of silence for slain demonstrators at a Kiev rally, while pro-Moscow activists in Donetsk paid tribute to a feared riot police unit accused of shooting at protesters in last month's violence.
"Russia! Russia!" the crowd shouted while waving Russian and Communist party flags in Donetsk, Mr Yanukovych's heartland.
"People have mobilised because their patience has run out: Ukraine has been drawn into the Europeans' and Westerners' political-economic game," Mr Robert Donia, one of the protest leaders, told Agence France-Presse, promising more demonstrations in the coming days.
Former boxer turned politician Vitali Klitschko called for Ukrainians "to be united".
"It's not important where people live - east or west of Ukraine, south or north," he said. He was then forced to scrap a Donetsk rally for fear of violence.
In Kharkiv, a northeastern city almost evenly split between Ukrainian speakers and Russian speakers, hundreds of Orthodox believers prayed for peace, kneeling in a central square.
In Odessa, local media said some 3,000 people sang Ukraine's national anthem on the Potemkin Stairs made famous by the silent film The Battleship Potemkin.
SHIPS SUNK TO BLOCK EXIT
Rival protests in the Crimean capital Simferopol passed off mostly peacefully as Ukrainians celebrated the 200th anniversary of 19th-century poet and national unity figure Taras Shevchenko.
But security incidents have multiplied in Crimea, with Ukrainian border guards reporting the arrival by land and sea of 60 Russian military lorries on the rugged peninsula of two million, and an attack by "Russian extremists" on a radar post.
In Sevastopol, pro-Moscow militants wearing balaclavas and bullet proof vests, joined by Cossacks wielding whips, attacked a small rally for Ukrainian unity.
Ukrainian authorities also accused Russia of deliberately sinking three of its own ships into a lake off the Black Sea to block the Ukrainian navy, yet another move by Russian forces who already surround Ukrainian military bases in the region.
On the Ukrainian side, 50 armoured personnel carriers were seen rolling in from the west out of the city of Lviv on Saturday in what the defence ministry said were pre-planned exercises.
SANCTIONS AND THREATS
As the crisis has escalated, Washington has imposed visa bans on targeted Russians and Ukrainians and warned of wider sanctions against Russia, while the EU has halted visa and other talks with Moscow.
Russia has warned that any sanctions would "inevitably have a boomerang effect" and a defence official said on Saturday Moscow may halt foreign inspections of its nuclear arsenal in response to "threats" from the US and Nato.
Adding to the tensions, state-run energy giant Gazprom has warned debt-stricken Ukraine it may cut off gas supplies over an unpaid US$1.89-billion bill - a move that could have knock-on effects across Europe.
Moscow continues to insist it has sent no extra troops to Crimea, despite parliament giving Mr Putin the greenlight to do so, and says it is only deploying units from its Black Sea Fleet already stationed there.