The Ukrainian military and Russian-backed separatists in eastern Ukraine accused each other on July 19 of shelling residential areas in rebel-held Donetsk.
Rebels said the heavy shelling — the first such attack on central districts of the city since a February cease-fire agreement — had killed one civilian, destroyed buildings, and started several fires.
Ukrainian military spokesman Serhiy Galushko said the army had intercepted rebel radio traffic that also suggested separatists planned to shell Donetsk.
Senior rebel commander Eduard Basurin denied the claim.
Kyiv also said one serviceman had been killed and seven wounded in separatist attacks in the past 24 hours.
In a separate development, rebels said they will withdraw all of their heavy weapons from the conflict zones later on July 19 in accordance with an agreement with the Organization for Security and Cooperation in Europe (OSCE).
Separatist leader Vladislav Deynego confirmed the implementation of the agreement, which stipulates that weapons with a caliber of 100 millimeters will be withdrawn at least three kilometers from the front lines.
More than 6,500 people have been killed since the conflict broke out in eastern Ukraine in April last year.
Attacks have lessened since the February 2015 truce agreement was brokered in Minsk, Belarus, but both sides accuse each other of violations.