Two servicemen died and three more were wounded after their armoured vehicle hit a mine in the Lugansk region, said military spokesman Oleksandr Motuzyanyk.
Two more soldiers were wounded in clashes near the village of Shyrokyne near the strategic port of Mariupol, the last major city in the conflict zone controlled by Kiev, he said.
Officials in charge of the anti-terrorist operation accused pro-Moscow militants of violating a fragile ceasefire 95 times yesterday.
Rebels for their part pointed the finger at Ukrainian troops, saying Kiev violated the truce 70 times over the past 24 hours by using tanks, grenade and mortar launchers.
Also Read
In February, French President Francois Hollande and German Chancellor Angela Merkel helped broker a peace deal for Ukraine in a last-ditch effort to stop months of fighting between pro-Russian separatists and Kiev forces.
The conflict has killed more than 6,000 people and displaced a million, according to the United Nations.