Four Ukrainian soldiers and at least as many civilians died Friday near the Russian border, in an upsurge of fighting that comes ahead of a meeting top foreign diplomats trying to salvage a four-way peace summit.
Ukraine officials linked the casualties to artillery shelling by pro-Russian rebels. Kyiv also tied the surge to new supplies of weaponry allegedly provided this week by Russia under the guise of humanitarian aid. Moscow insists its latest relief convoy was carrying civilian supplies.
In Kyiv, meanwhile, authorities announced ministerial talks on Monday by top diplomats of Germany, Russia, Ukraine and France, in a push to clarify the time frame and agenda for a possible summit.
Ukraine had touted the summit - tentatively set for Thursday the Kazakh capital, Astana - as a key step in the push for a sustainable truce in eastern Ukraine.
But Germany and France have questioned whether such a summit can take place without further progress on an earlier peace plan signed by rebel leaders and Kyiv in September.
On Thursday, German Foreign Minister Frank-Walter Steinmeier cast doubt on prospects for the summit, saying the four leaders would only meet in Kazakhstan if they believed tangible progress could be made.
Separately, German Chancellor Angela Merkel said all 12 points of the September truce agreement had to be fully implemented before Western governments would lift sanctions slapped on Russia for its widely-perceived support for the rebellion.
Under the September truce deal, both sides agreed to a cease-fire and the withdrawal of fighters and military hardware from the war-torn east. But international monitors say more than 1,300 of Ukraine's 4,700 war fatalities have occurred since the so-called Minsk Protocol was signed.