Mournful chants drifted over the graves of the nameless soldiers, most of whom fell in the battle of Ilovaisk last August after Ukrainian forces found themselves encircled, outgunned, and vastly outnumbered by Russian-backed rebels.
Authorities have spent months trying to identify the bodies and find relatives, but without success.
"It's horrible to think that somewhere their parents are waiting for them, their children, brothers, sisters," said local resident Olga Bondarenko, who had come to pay her respects at the cemetery in the south-eastern region of Zaporizhzhya.
Hundreds of soldiers are believed to have been killed in the encounter, but official figures are much lower.
Government efforts to recover bodies were hampered by the fact they lay in separatist-held territory.
Afterwards an unwillingness from relatives to undergo DNA testing also held up the process, news agency Interfax Ukraine quoted regional military official Oleksander Beda as saying.
"Until the end they hope that their loved ones, who were missing in action, were alive and either captured or in hospital ... You can understand them - hope dies last of all," he was quoted as saying.
In October, a parliamentary report on Ilovaisk listed a series of military mistakes and concluded that "the causes of the ... tragedy are fundamental problems in the organization of the country's system of defense".
It said it was not able to establish the true number of casualties due to a lack of data from the Ministry of Defence and General Staff.
More than 6,600 soldiers, separatists and civilians have been killed since fighting between Ukrainian troops and rebels seeking independence from Kiev erupted in April 2014, according to United Nations estimates.
Violence has continued despite a ceasefire deal signed in February with both sides accusing the other of violations.
Sixteen servicemen have been killed by shelling or landmine explosions since the start of August, while 29 were killed on the frontline in July.
"To think that this could happen to our country, to our boys," Bondarenko said, her voice choking with tears.
Clouds of red dust rose into the air as soldiers shoveled earth into the graves, each marked with a plain cross and a plaque inscribed with the words: "Unknown soldier."
Source: Google News