The Ukrainian military said another 10 soldiers were wounded in Grad rocket and mortar attacks by pro-Russian insurgents based around the eastern industrial city of Donetsk.
The upsurge in violence came as the foreign ministers of Ukraine, Russia, Germany and France ended a meeting Monday without being able to set a date for a hoped-for peace summit on ending the conflict.
The Donetsk adminstration said two civilians were killed in the rebel stronghold overnight. Another person was killed in a small town to the northeast of Donetsk.
Ukrainian military spokesman Andriy Lysenko said the government's military positions had come under attack 84 times since Monday morning -- about six times the usual number recorded in the nine-month war.
The latest casualties were reported after the foreign ministers of Germany and France failed to help their counterparts from Moscow and Kiev bridge their differences over ways to end a conflict that has claimed more than 4,700 lives.
Ukraine accuses Russia of arming the insurgents and refusing to withdraw its own troops from the eastern war zone -- soldiers Moscow denies having ever sent.
Kiev accuses the rebels of escalating their strikes in order to undermine the chances of Russia agreeing to a settlement that preserves Ukraine's eastern border.
