"The head of the DNR, Alenksandr Zakharchenko, has died as a result of a terrorist act," a spokesperson of the self-proclaimed republic's administration told journalists, revealing no details of the incident.

"An improvised explosive device was planted inside the café ... right near the entrance," Aleksandr Kazakov, an advisor to the DNR leader, told RT, adding that the killers apparently knew that Zakharchenko would arrive at the café and were "waiting" for him. A state of emergency has been imposed, Kazakov said, adding that borders with both Ukraine and Russia were sealed as the security services are "actively searching for the potential perpetrators."

One of Zakharchenko's deputies also sustained severe injuries in the blast while several bodyguards died in the incident, Kazakov said. He added that Zakharchenko died at the scene as well, contrary to the earlier reports suggesting he was injured and succumbed to his wounds in a hospital.

Moscow condemned 42-year-old Zakharchenko's murder, adding that it could be detrimental to the whole peace process in Ukraine. The death of the DNR leader could have a particularly negative impact on the implementation of the Minsk Agreements, Konstantin Kosachev, the head of the Russian Senate's International Affairs Committee, said.

There is "every reason to believe" that Zakharchenko's murder was orchestrated by Kiev, which "has repeatedly resorted to such methods to get rid of dissidents and undesirables," Maria Zakharova, spokeswoman for the Russian Foreign Ministry, said.

According to Alexander Kazakov, adviser to the DPR head, the suspects have been detained following an operation.

© @Russ_Warrior/Twitter
The explosion caused by a bomb took place inside "Separ" café, near to Zakharchenko's house,

"At this point, a state of emergency has been introduced in the republic, the borders have been closed, suspects have already been detained," Kazakov said in an interview with the television channel Russia-1.

Kazakov added that despite the announced detention of the suspects, the borders of the DPR, including those with Russia and Lugansk People's Republic, are closed as operation is in course.

Following the death of the DPR Head, the deputy prime minister Dmitry Trapeznikov was appointed as Zakharchenko's successor.

"The decision of the DPR territorial defense headquarters: in accordance with the paragraph 1 of the article 102 of the DPR Constitution, to appoint Trapeznikov Dmitry Viktorovich, the deputy head of the council of ministers, interim [DPR] leader in connection to the death of [DPR] head Alexander Zakharchenko," the decision, read out by Trapeznikov himself.

Russia's Statements on the Assassination

Commenting on the issue, Russian President Vladimir Putin said that the incident was an attempt to destabilize the situation in the region and bring the people of Donbass to their knees, adding that the hoped to see organizers and perpetrators of the "despicable assassination" found and punished.

The President also expressed his deep condolences, that Russia will always be with the people of Donbass.

"I want to express condolences... to relatives and friends of Alexander Vladimirovich Zakharchenko and all people of Donbass. Russia will be always with you," Putin said.

Following the explosion, Russia's Investigative Committee has opened a criminal investigation, considering the incident to be an act of international terrorism, spokeswoman Svetlana Petrenko said.

"Russia's Investigative Committee, based on the existing international experience in the investigation of terrorist acts, is ready to provide all possible assistance to law enforcement agencies of the Donetsk People's Republic in the probe," Petrenko added.

In February 2017, separatist commander Mikhail Tolstykh, 36, whose nom de guerre was Givi, died in an explosion in his office in Donetsk.

Another separatist commander -- Arseny Pavlov, known as Motorola -- was killed when a bomb exploded in an elevator in his apartment block in Donetsk in October 2016.

On January 1, 2015, Aleksandr Bednov, a separatist commander in Luhansk, was killed resisting arrest by fellow separatist authorities on charges he ran a torture chamber in the basement of a rebel-held building.