Ukraine crisis: Russia steps up Ukraine rhetoric
Russian Prime Minister Dmitry Medvedev: "Result of an armed mutiny"
Russia has stepped up its rhetoric against Ukraine's new Western-leaning leadership as tensions rise over the ousting of President Viktor Yanukovych.
Russian PM Dmitry Medvedev said interim authorities in Kiev had conducted an "armed mutiny".
And the Russian foreign ministry said dissenters in mainly Russian-speaking regions faced suppression.
Earlier, Ukraine's interim interior minister said an arrest warrant had been issued for Mr Yanukovych.
MPs voted to remove Mr Yanukovych on Saturday. His whereabouts are unknown but he was reported to have been in the Crimean peninsula on Sunday.
Russia, angered at the loss of its political ally, has already recalled its ambassador for consultation.
Unrest in Ukraine began in late November when Mr Yanukovych rejected a landmark association and trade deal with the EU in favour of closer ties with Russia.
Meanwhile, EU foreign affairs chief Catherine Ashton has arrived in Kiev to discuss financial and political support for Ukraine's new leaders.
Ukraine is in danger of defaulting on its debts as a Russian aid package now seems unlikely to proceed.
Baroness Ashton began her visit by laying flowers in Independence Square to those killed in clashes between protesters and police.
Mr Medvedev, quoted by Russian news agencies, suggested that Western countries that accepted Ukraine's new authorities were mistaken.
"Strictly speaking, there is no-one for us to communicate with there today," he said.
"The legitimacy of a whole number of organs of power that function there raises great doubts.
"Some of our foreign, Western partners think otherwise. This is some kind of aberration of perception when people call legitimate what is essentially the result of an armed mutiny."
He added: "We do not understand what is going on there. There is a real threat to our interests and to the lives of our citizens."
Ukraine's foreign ministry quickly responded to Mr Medvedev's concerns for Russian citizens in Ukraine, saying they were "unfounded".
Activists are still manning barricades in Kiev 
Interim President Olexander Turchynov met EU foreign policy chief Catherine Ashton in Kiev 
Tensions between pro- and anti-Russian supporters are high in Sevastopol, Crimea However, Russia's foreign ministry also issued a strongly worded statement saying a "forced change of power" was taking place in Ukraine and accused interim leaders of passing new laws "aimed at infringing the humanitarian rights of Russians and other ethnic minorities".
"A course has been set towards suppressing dissenters in various regions of Ukraine by dictatorial, and sometimes even terrorist, means," a statement said.
It did not give any details.
On Sunday, Ukraine's parliament lowered the official status of the Russian language by cancelling a law brought in by Mr Yanukovych.
Also on Sunday, US National Security Adviser Susan Rice warned Russia it would be a "grave mistake" to intervene militarily.
Ukraine's parliament has until Tuesday to form a new unity government.
Interim interior minister Arsen Avakov said on Facebook that a criminal case had been opened against Mr Yanukovych and other officials over "mass murder of peaceful citizens".
The statement said Mr Yanukovych was last seen in Balaklava on the Crimean peninsula on Sunday.
It said that after dismissing most of his security detail, he had left by car for an unknown destination, accompanied by an aide.
The statement did not name the other figures covered by the warrant.
According to media reports, Mr Avakov and Valentyn Nalyvaychenko - appointed by parliament to oversee security matters - have travelled to Crimea to defuse tensions.
The peninsula is an autonomous region where the majority of the population is ethnically Russian.
Crimea and some pro-Russian areas in the east have seen protests against the overthrow of Mr Yanukovych, sparking fears that Ukraine could be split apart by separatist movements.
Ukraine's health ministry says 88 people, mostly anti-Yanukovych protesters but also police, are now known to have been killed in last week's clashes.
Thousands of people remain in Kiev's Independence Square, the Maidan.
Correspondents say the atmosphere in the square is now largely calm, and it has become a shrine to those killed.
Interim Finance Minister Yuriy Kolobov has said Ukraine needs around $35bn (£21bn) in urgent foreign aid and asked for an international donors' conference to be held.
Moscow recently agreed to provide $15bn for Ukraine's struggling economy - a move seen as a reward for Mr Yanukovych's controversial decision not to sign the long-planned trade deal with the EU.
But there are fears Moscow could withdraw that offer. Ukraine has state debts of some $73bn, with around $6bn to be paid this year.
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