Six soldiers have been killed and 12 injured as fighting has flared in eastern Ukraine in the past 24 hours, despite a cease-fire.
Ukrainian military spokesman Andriy Lysenko said on April 14 that the casualties were the result of "serious provocations" by Russian-supported separatists.
Lysenko said the situation in eastern Ukraine was "unstable" with attacks "by the enemy continuing in almost all directions."
He added that the most intense shelling occurred in the villages of Shyrokyne and Pavlopil, near the southern seaport of Mariupol, and in areas near the rebel-held regional capitals of Donetsk and Luhansk.
The six deaths are the highest toll in eastern Ukraine in 10 days.
The announcement came hours after the Ukrainian, German, French, and Russian foreign ministers met in Berlin and expressed "grave concern" over cease-fire violations.
Fighting in the conflict that has killed more than 6,000 people in a year has eased considerably since a cease-fire deal was signed in Minsk in February.