A militant group of Ukrainian nationalists calling themselves the Ukrainian Insurgent Army (UPA) have claimed responsibility for the assassinations of a prominent pro-Russian journalist and a former aide of deposed pro-Russian president Viktor Yanukovych, who were both killed within hours of each other.
The group declared responsibility for the murders in an email sent to political expert Volodomyr Fesenko addressed to members of the new Opposition Bloc government. They also said they were behind the deaths of a number of other pro-Russian figures, some of which were previously ruled as suicides.
In the email, the group reportedly tells those guilty of "anti-Ukrainian" activity they have until Monday to leave the country.
"We are unleashing a ruthless insurgency against the anti-Ukrainian regime of traitors and Moscow's lackeys. From now on, we will only speak to them using the language of weapons, all the way to their elimination," Fesenko said, reading the email.
The email was sent after news editor Oles Buzina was shot dead while jogging outside his home Thursday afternoon at 1.20pm local time, just hours after the murder of former Yanukovych aide Oleh Kalashnikov, who was gunned down outside his apartment Wednesday evening.
Both Buzina and Kalashnikov were said to have been involved in pro-Yanukovych protests during last year’s revolution, which eventually saw Yanukovych flee pro-EU demonstrations in Kiev.
However, Security Services spokesman Markiyan Lubkivsky questioned the authenticity of the email, saying the author had been traced back to an address in Germany and made grammatical errors suggesting the message was not written by a native Ukrainian speaker.
Lubkivsky also denied the existence of the UPA, but Ukrainian far-right political expert Anton Shevkhovtsov was cited by the BBC saying the group showed signs of activity in January 2014 as a "small radical nationalist group" which took part in the occupation of the Kiev City Hall.
Ukrainian Interior Ministry aide Anton Geraschenko said Buzina and Kalashnikov may have been targeted as they were key eye-witnesses to abuses carried out against pro-EU protesters in Kiev’s Maidan Square.
“Everyone who was involved in organizing and financing Anti-maidan, or other illegal acts against Maidan, and feels their life is under threat, are advised to come to law enforcement organs to not go the same way as Kalashnikov and Buzyna,” Geraschenko wrote on Facebook.
Speaking to the 112 television channel, Gerashchenko also said the murders may be being carried out by the Russian secret services.
Ukrainian lawmaker Sergei Leshchenko concurred with Gerashchenko. “Looks like FSB provocation,” wrote Leshchenko on Twitter.
Lawmaker Volodymyr Ariev also told The Guardian, “It looks as if an FSB shooting brigade arrived and is shooting them off.”
“It easily fits into the Russian narrative that Ukraine is all about fascists, a country where even the basic right for life is violated,” he said.
President Petro Poroshenko meanwhile claimed the murders were part of a “deliberate provocation” to destabilize the country
“It is evident that these crimes have the same origin,” Poroshenko said. “Their nature and political sense are clear. It is a deliberate provocation that plays in favour of our enemies.
“It is aimed at destabilizing the internal political situation in Ukraine and discrediting the political choice of the Ukrainian people.”
At least six allies of former president Yanukovych died in mysterious circumstances between January and March, with police saying they had committed suicide. However, the General Prosecutor’s office said it was launching criminal investigations into four of the cases.
Two parliamentary deputies from Yanukovych’s Party of Regions were found with gunshot wounds in March. One party member also died after falling from a window, while another member was found hanged.
Yanukovych also lost his son last month in an apparent car accident near Lake Baikal in Russia.
Russian President Vladimir Putin, who was on a live television call-in show when he received the news of Buzina’s assassination, accused Kiev of carrying out political killings.
"In Ukraine, which claims to be a democratic state and has aspirations toward democratic Europe, there has been nothing similar. Where are the killers of these people? Where are the people who carried them out and those who ordered them? They aren't there. In Europe and North America they prefer not to notice this," Putin said.
Ceasefire under threat
A pro-Russian rebel leader fighting for an independent state in eastern Ukraine warned the Minsk peace deal holding a ceasefire in the region between troops and separatists will fail unless Kiev recognizes the self-proclaimed Donetsk People’s Republic.
Speaking to the BBC, rebel leader Aleksandr Zakharchenko said, "Ukraine has stopped paying welfare, pensions and other payments that are obligatory for a state to pay its citizens...They don't do it, so they've de facto recognized us."
Although the Minsk deal states the rebel-held areas are to remain part of Ukraine, Zakharchenko claims Ukraine has a responsibility to recognize the region’s independence, and accuses Kiev of not sticking to agreements.
"Ukraine doesn't want to resolve all the issues...If you agree to resolve something, then you need to act and move forward, and resolve everything that's included,” Zakharchenko said.
"If that doesn't happen, then the Minsk Agreement is unfulfilled, and it renders all the meetings in Minsk pointless.”
According to a report released by the OSCE Special Monitoring Mission (SMM) on April 16 three ceasefires organized by the Joint Centre for Control & Coordination (JCCC) between rebels and troops were broken within minutes by an “unidentified third party.”
“According to both Ukrainian Armed Forces and Russian Federation Armed Forces officers at the observation point, an unidentified 'third party' was provoking the two sides,” Ukrainian and Russian mediators told OSCE representatives, without mentioning the direction of the fire.
Russia and Ukraine have been at loggerheads ever since the ousting of pro-Russian president Yanukovych in February 2014.
The crisis led to the autonomous government in Crimea, which is dominated by ethnic Russians, to declare independence from Ukraine and eventually be annexed by Russia following a referendum the following month.
Over 6,000 people have died in the fighting between pro-Russian rebels and the Ukrainian government. Kiev views the conflict as a Russian invasion of its territory.