MOSCOW (AP) -- A blast in a war-themed cafe in eastern Ukraine on Friday killed the most prominent leader of the Russia-backed separatists who have fought Ukrainian forces since 2014, rebel officials said.
The death of Alexander Zakharchenko, prime minister of the self-declared Donetsk People's Republic, underlined the dismal prospects for resolving the conflict that has killed more than 10,000 people.
Rebel and Russian authorities blamed the Ukrainian government, with some suggesting that the United States had a role, while a top Ukrainian security official said the blast was likely the result of the separatists' factional infighting or an operation by Russian special forces.
Deputy rebel military commander Eduard Basurin said the explosion in the region's capital of Donetsk was caused by a bomb planted in the restaurant, which was named "Separ" in honor of the separatists and decorated with camouflage netting hanging from the eaves.
Seriously injured in the blast was Alexander Timofeev, the revenues and taxes minister for the separatists, according to the rebels' DAN news agency. In September 2017, Timofeev was injured in another bombing in Donetsk, the region's capital.
The Donetsk People's Republic, along with a separatist republic in neighboring Luhansk, has fought Ukrainian forces since 2014, the same year Zakharchenko became the DPR's prime minister. More than 10,000 people have died in the conflict.
Fighting fell off significantly after the leaders of Russia, Ukraine, Germany and France in 2015 signed an accord in Minsk, Belarus, on ending the violence. But most of the agreement's provisions remain unfulfilled and clashes break out sporadically.
"The assassination of the DPR head makes the Minsk accords devoid of sense," Russian parliament speaker Alexander Volodin said.
Russian President Vladimir Putin lauded Zakharchenko, who was 42, as "a true people's leader" and promised Donetsk residents that "Russia always will be with you."
Denis Pushilin, the speaker of the separatists' parliament, blamed Ukraine's forces for the explosion, calling it "the latest aggression from the Ukrainian side," according to DAN. A statement from the rebel command said "it was conducted by special operations forces of Ukraine under control of U.S. special services."
"Instead of fulfilling the Minsk accords and finding ways to resolve the internal conflict, the Kiev war party is implementing a terrorist scenario," Russian Foreign Ministry spokeswoman Maria Zakharova said of Zakharchenko's death. "Having failed to fulfill the promise of peace, apparently they decided to turn to a bloodbath."
Igor Guskov, chief of staff of the Ukrainian Security Service, rejected allegations of any involvement, saying: "We have reason to believe that the death of Zakharchenko may be the result of an internal criminal conflict among the rebels ... but we do not exclude that it was an attempt by Russian special services to remove this odious figure."
There have been several assassinations or attempted slayings of prominent rebels in recent years. It never was established if pro-Kiev attackers were responsible or if the violence resulted from disputes within the rebel ranks or Moscow's possible desire to eliminate individuals it found inconvenient.
Among the prominent separatists who have been targeted are former Luhansk leader Igor Plotnitsky, who was severely injured in 2016 when a bomb exploded near his car; Arsen Pavlov, a feared squadron leader known as "Motorola," who died when the elevator of his apartment building was bombed; and fighter Mikhail Tolstykh, whose office is believed to have been hit by a shoulder-fired rocket.
Russia denies providing troops or equipment to the separatists despite widespread allegations it has done so. Russia is believed to have supplied a mobile Buk missile launcher that a team of international investigators alleges shot down a Malaysian passenger jet while flying over rebel territory in 2014, killing all 209 people aboard.
The rebellion in Donetsk and Luhansk arose soon after pro-Russia Ukrainian President Viktor Yanukovych was driven from power amid mass protests in February 2014. Russian-speakers predominate in the two regions, and separatist sentiment skyrocketed.
Encouraged by Russia's annexation of Crimea, which also came after Yanukovych's ouster, rebel leaders initially hoped their regions would be absorbed by Russia as well.