Story highlights

Separatists fired artillery toward Mariinka, Ukrainian general command media office says

It says 200 separatists attacked Ukrainian positions, denies reports that 25 Ukrainian soldiers were wounded

Clashes began because of "provocations" by Ukrainian forces, separatist spokesman says

CNN  — 

Heavy artillery fire was reported Wednesday around the city of Donetsk in eastern Ukraine in what observers described as some of the worst fighting in the months since a shaky ceasefire was declared.

Separatists fired heavy artillery from Donetsk toward Mariinka early Wednesday, the Ukrainian general command media office said. Controlled by Ukrainian government forces, Mariinka sits on a strategically vital highway to the west, where checkpoints mark the end of separatist-controlled territory.

The general command said 200 separatist militants attacked Ukrainian positions, with an exchange of fire for six hours. It denied reports that 25 Ukrainian soldiers were wounded or that their positions were surrounded.

Eduard Basurin, a spokesman for the separatist Donetsk People’s Republic, confirmed the clashes in Mariinka, saying the fighting began because of “provocations” by Ukrainian forces. He added that Ukrainian forces shelled the city of Donetsk’s Petrovsky and Kirovsky districts overnight. Separatists hold Donetsk.

A Ukrainian serviceman fires a grenade launcher on the frontlines near Donetsk on Saturday, May 30.
Intense fighting flares in eastern Ukraine
01:42 - Source: CNN

Vladimir Kononov, the self-declared defense minister for the Donetsk People’s Republic, told a news agency working with the separatists that their forces could not have stormed the Ukrainian controlled-Mariinka because they have always had a presence there.

An attempt to say that we are storming Mariinka – that’s a provocation by Kiev,” Kononov told the DAN news agency. “We are already there in Mariinka.”

He called the announcements by the Kiev authorities “another attempt to blacken the DNR’s name,” using an acronym for the Donetsk People’s Republic.

Separatist officials gave differing figures on the number of injured from the reported shelling of Donetsk. Russian state news agency RIA Novosti quoted the self-declared mayor of Donetsk, Igor Martynov, as saying that four civilians died and two were injured in the Lidiyevak and Kuibishevski regions, respectively.

Other separatist media reports suggested larger numbers of civilians were injured.

In a sign that both sides may be preparing for further fighting this summer, monitors from the Organization for Security and Cooperation in Europe in Ukraine “visited many heavy weapons sites on both sides and have recorded missing weaponry,” said Michael Bociurkiw, a spokesman for the organization.

Residents of Donetsk, who did not want to be named for security reasons, told CNN they could hear outgoing and incoming shelling loudest in the western district of Petrovsky and northwestern district of Kirovsky. Social media reports also suggested street fighting in Mariinka.

A European diplomat, speaking anonymously because of the sensitivity of the issue, told CNN that early reports suggested a fresh offensive by separatists toward Mariinka, using heavy weapons, including Grad rockets. The diplomat added there were also overnight reports of heavy shelling of Donetsk.

“It will take a while to verify,” the diplomat said, “but if this is the case, it would be a major, major ceasefire violation.”

Shelling, bullets and explosions: This is Ukraine’s ceasefire

In February, Ukraine, Russia, pro-Russian separatists, France and Germany signed an agreement in Minsk, Belarus, calling for a truce.

Journalists Victoria Butenko and Denis Lapin reported from Kiev, Ukraine. CNN’s Nick Paton Walsh contributed to this report.