Ukrainian forces denied allegations by pro-Russian separatists that they had launched a new offensive in eastern Ukraine on Thursday, saying they were strictly adhering to a ceasefire agreement that has come under increasing strain.
Sporadic violence has flared since the Sept. 5 truce, but the ceasefire has looked particularly fragile this week with both separatists and the central government accusing each other of violating the terms of a 12-point peace plan.
Earlier on Thursday Andrei Purgin, deputy prime minister of the self-proclaimed Donetsk People's Republic, said the Ukrainian army had launched "all-out war" on rebel positions, Russian news agency RIA reported.
Ukrainian military spokesman Vladyslav Seleznyov denied this, saying the army remained in agreed positions.
"We refute these allegations...we're strictly fulfilling the Minsk memorandum (on a ceasefire). We remain within the previously defined boundaries, in our positions. We're not advancing," Seleznyov said by telephone.
A Reuters witness in the rebel stronghold of Donetsk said there was no sign the conflict was escalating.
Representatives of the separatist regions earlier put out a joint statement calling for a redraft of the Minsk deal, which established a ceasefire in exchange for Kiev granting "special status" to eastern territories.
Rebels say Ukraine has violated the deal by seeking to revoke a law that would have granted eastern regions autonomy. Kiev says this decision is a consequence of Sunday's separatist leadership elections which it says go against the September agreement.
Separately, the Ukrainian military said three soldiers had been killed on Thursday, reporting a total of 26 separate artillery clashes with separatists.
More than 4,000 people have died since pro-Russia separatist rebellions broke out in the industrialised east following the overthrow of Ukraine's Moscow-backed leader Viktor Yanukovich in February and Russia's subsequent annexation of Crimea.