SIMFEROPOL, Ukraine (AP) — Ukraine’s acting government issued a warrant Monday for the arrest of President Viktor Yanukovych, last seen in the pro-Russian Black Sea peninsula of Crimea, accusing him of mass crimes against protesters who stood up for months against his rule.

Calls are mounting in Ukraine to put Yanukovych on trial, after a tumultuous presidency in which he amassed powers, enriched his allies and cracked down on protesters. Anger boiled over last week after snipers attacked protesters in the bloodiest violence in Ukraine’s post-Soviet history.

Ukraine’s acting interior minister, Arsen Avakhov, said on his official Facebook page Monday that a warrant has been issued for the arrest of Yanukovych and several other officials for the “mass killing of civilians.” At least 82 people, primarily protesters, were killed in clashes in Kiev last week.

Avakhov said Yanukovych arrived in Crimea on Sunday and relinquished his official security detail then drove off to an unknown location.

Fears that Ukraine could splinter into rival pro-Russia and pro-EU camps is spurring intense activity in the West to keep the country together, while also seeking to placate Russia over Kiev’s tilt away from Moscow.

EU foreign policy chief Catherine Ashton is to begin a two-day visit to Kiev on Monday to speak with Ukraine’s interim leaders appointed after a bloody and tumultuous week of historic change.

Ashton, German Chancellor Angela Merkel, French President Francois Hollande and US National Security Adviser Susan Rice all stressed separately Sunday that Ukraine must forge a political solution that guarantees its “unity.”

Though break-up is not yet being seen, tensions are clear in the pro-Russian east of Ukraine over the turn of events, which saw Yanukovych and his government ousted, and with them the closer ties to Moscow they had been promoting.

“The fascists have taken power in Kiev!” yelled one speaker to an angry crowd of 10,000 people in Ukraine’s southeastern port city of Sevastopol — home to Russia’s Black Sea fleet.

The incoming Kiev leadership has made clear it will revive plans Yanukovych scrapped to push Ukraine closer to the European Union.

“We are ready for a dialogue with Russia… that takes into account Ukraine’s European choice, which I hope will be confirmed in (presidential) elections” set for May 25, Ukraine’s new interim president, Oleksandr Turchynov said in a television address.

Key to Ukraine’s pro-EU aspirations, though, will be international financial aid to help the country stave off a looming default brought on by the months of upheaval and by decades of mismanagement and corruption.

Ashton will be discussing “measures to stabilize the economic situation,” her office said in a statement.

Hollande said in his own statement that France, through the EU, would “fully support… the political reforms and economic modernization of Ukraine.”

German Foreign Minister Frank-Walter Steinmeier also said his country would back economic help to debt-laden Ukraine.

“A bankrupt Ukraine would be a huge weight for its big neighbor to the east (Russia) as well as for the European Union,” he told public German television network ZDF.

“It’s reasonable to discuss right now… how to stabilize Ukraine economically.”

Russian loan halted

That discussion has become all the more important because Russia is backing away from a $15 billion loan it had agreed to give in December.

Moscow says the political order in Ukraine is too unclear to approve tranches of the remaining $12 billion.

In a move highlighting Russia’s deep displeasure with Ukraine’s shift West, late Sunday it recalled its ambassador to Kiev for “consultations.”

With default a very real risk, the United States and the International Monetary Fund said Sunday they stood ready to assist Ukraine.

“The IMF remains in the best position to help states like Ukraine deal with their economic challenges,” US Treasury Secretary Jacob Lew said in Australia, where he was attending a G20 meeting. He added that he held talks with Russian Finance Minister Anton Siluanov about Ukraine.

The contest between Russia and the United States added a Cold War-style cast to the turmoil in Ukraine.

Washington had gone out of its way to try to herd Kiev back towards the EU, while Moscow was intent on locking it into a customs union of former Soviet states.

Similarly, British finance minister George Osborne, who is in Singapore for a two-day official visit after attending a G20 meeting in Sydney, said Monday the EU could provide financial aid alongside the IMF.

“It is very, very early days, early hours, but the people of Ukraine seem to have demonstrated their wish to take their country into the future and to have stronger links with Europe and I don’t think we should be repelling that, we should be embracing that,” Osborne told reporters.

“We should be there ready to provide financial assistance through organisations like the IMF and of course a lot of this will take the form of loans and the like,” he continued.

Fears that Ukraine’s debt-laden economy is facing default have sparked panic on markets, with bond yields rising sharply and the hryvnia currency losing a tenth of its value in the span of a few weeks.

“It is very early days, we have to have of course a legitimate political authority that we can deal with, but there are very encouraging signs in that regard,” Osborne said.

Bid to defuse Russian anger

In a bid to defuse Russian anger over the outcome, Merkel on Sunday held a telephone conversation with Russian President Vladimir Putin in which “both agreed that Ukraine must quickly get a government capable of acting and its territorial integrity must be preserved,” according to a German government spokesman.

US President Barack Obama had already spoken with Putin on Friday, before Yanukovych was toppled, but few details of that conversation were released.

On Sunday, Obama’s National Security Adviser emphasized that “it’s not in the interests of Ukraine or of Russia or of Europe or of the United States to see the country (Ukraine) split.”

Asked on television network NBC about whether Russia could send forces to restore a pro-Moscow government in Kiev, Rice warned: “That would be a grave mistake.”

US Secretary of State John Kerry, in a call to his Russian counterpart, also underscored Washington’s expectation that “Ukraine’s sovereignty, territorial integrity and democratic freedom of choice will be respected by all states.”

He expressed hope that “the Russian Federation will join with us… to help Ukraine turn the page and emerge from this crisis stronger, united and moving forward through new elections and critically needed reforms.”