A bomb in a cafe in the city of Donetsk killed Alexander Zakharchenko, head of the Moscow-backed self-proclaimed Donetsk People’s Republic, on August 31.

Zakharchenko died on the spot from a fatal head injury. According to his advisor Alexander Kazakov, an improvised explosive device planted inside the cafe. "It was an improvised explosive device, its main principle of action — a blast wave and fire," Interfax news agency quoted him as saying the next day. "The blast occurred as they were walking into the cafe, the device was planted above the door inside. The bodyguard, who walked first, was killed instantly."

As a result of the blast, Zakharchenko's bodyguard was killed, while the Donetsk People's Republic's Minister of Revenues and Duties Alexander Timofeyev was seriously injured and later died of his wounds.

Zakharchenko is the latest prominent pro-Russian leader of the Donetsk People's Republic to be killed since a ceasefire was secured with Kyiv in 2015.

In February 2017, prominent pro-Russian rebel field commander Mikhail Tolstykh, nicknamed Givi, was killed by a rocket fired at his office in Donetsk. Unknown attackers fired a portable Shmel incendiary rocket launcher at the building, local officials said, which points to a targeted killing.

The incident followed October's assassination of another rebel field commander Arseniy Pavlov, known as Motorola, in a bomb blast in the elevator of his home, also in Donetsk. The commander gained notoriety after publicly claiming to have personally executed 15 captive Ukrainian government soldiers.

In the past, authorities of the self-proclaimed so-called Donetsk People's Republic and Luhansk People's Republic have blamed assassinations of well-known rebels on Kyiv, which sought them for crimes against Ukraine's territorial integrity. However, some security experts believe Russian special forces could be behind these actions, removing rebel commanders who do not comply with orders sent from Moscow.

According to Russian media, the self-proclaimed Donetsk People's Republic will be temporarily led by its Deputy Prime Minister Dmitry Trapeznikov after the killing of Zakharchenko.

Meanwhile, Vasyl Hrytsak, head of the SBU security service in Kyiv believes the rebel leader was eliminated by Moscow.

"In my opinion, the situation is predicted. All those who in 2014 facilitated the introduction of Russian troops to Donbas, who contributed to the creation of pseudo-national republics are being eliminated," Interfax quoted Hrytsak as saying on September 1. "We believe that a methodical elimination of those who know too much and who have blood on their hands, those who are no longer needed as witnesses is being carried out."

Meanwhile, Russian Foreign Minister Sergei Lavrov called the same day murder of Zakharchenko "an open provocation aimed to derail the Minsk agreements' implementation", according to Russian media.

Over the past two years, the Normandy format representatives (Germany, France, Ukraine and Russia) failed to secure any significant progress during talks on settling the conflict, which erupted in 2014 as pro-Russian separatists in East Ukraine broke away from Kyiv's central control. Around 11,000 servicemen, rebels and civilians have so far died.

In 2016, the leaders of Ukraine, Russia, Germany and France agreed in Berlin to draft a new road map for the implementation of the Minsk peace accords reached in the capital in 2015. The road map is intended to ensure the success of political, security and humanitarian measures in the Donbas region.

The Kremlin rejects any security preconditions and wants the polls to go ahead in the Donbas at the earliest date. The position was strengthened by German Chancellor Angela Merkel’s comments at the Berlin summit that Ukraine should regain full control of the occupied border “only at the end of the process”, a position also indicated by France’s then president Francois Hollande a few days earlier.

However, the sides agreed that OSCE observers could move freely up to the border, Merkel added in widely reported comments.

Ukrainian President Petro Poroshenko in turn insisted that “all foreign troops” must be unconditionally pulled out from rebel-held areas before local elections, a reference to the Russian military, despite Moscow’s insistence that it has no forces in Ukraine.

Other measures sought include a more durable ceasefire, observance of the disengagement regime, the release of prisoners, and unrestricted access for OSCE mission staff to all areas, an issue that has constantly hampered efforts to monitor both sides’ commitment to demilitarisation in the conflict zone.

Earlier, Poroshenko said that Kyiv favours the deployment of a full-scale UN peacekeeping mission in Donbas. However, the mission's purpose "should be not to perpetuate the Russian occupation and legalise the Russian military presence but ensure durable peace in certain districts of the Donetsk and Luhansk regions of Ukraine and fully restore our state's territorial integrity".

Kyiv also insists that the UN mission should comply with the guiding principles of UN peacekeeping operations, which a priori rule out the participation of an aggressor country or a party to the conflict in it, which mean that the Ukrainian leadership opposes including the Russians in the mission.