Three Ukrainian soldiers and two civilians have been killed over the past 24 hours in fighting in the separatist east, a Ukrainian military spokesman said Sunday.
The latest deaths highlight the fragile nature of a February ceasefire aimed at halting the conflict and come shortly before talks next week aimed at salvaging the deal.
Fighting has intensified recently around key hotspots on the frontline in industrial eastern Ukraine, particularly the outskirts of the strategic government-held port city of Mariupol and Donetsk airport.
Two soldiers were killed on Sunday and a third was wounded in a battle in Marinka, about 30 kilometres (20 miles) west of the rebel stronghold of Donetsk, a local military spokesman Evgen Silkin told AFP.
In the neighbouring Lugansk region, which is also held by the pro-Russian separatists, a soldier was killed in fighting with rebels in a village near Debaltseve — a key town which came under rebel control shortly after the February truce, the regional pro-Kiev governor Gennady Moskal said.
He said a 55-year-old civilian and his 14-year-old son were also killed by a makeshift bomb which blew up in Stanitsa Luganska.
Another soldier was killed in Shirokine, another flashpoint just 10 kilometres away from Mariupol, the last remaining government-held city in the conflict zone.
The Organisation for Security and Cooperation in Europe, which has monitors on the ground in eastern Ukraine, has denounced a surge in violations of the February truce.
A top Ukrainian envoy is due to meet rebel leaders in the Belarus capital Minsk on Tuesday for European-mediated talks aimed at salvaging the ceasefire and also agreeing on the status of the separatist east.
The conflict, which erupted in April 2014, has claimed the lives of almost 6,300 people.