One Ukrainian soldier has been killed and 17 troops and civilians wounded in fighting over the past 24 hours, officials said Saturday, as clashes continued to break a nominal truce.

One paratrooper was shot dead by a sniper in the ruins of Donetsk's international airport, where Ukrainian forces are almost surrounded by rebels, Ukraine's military said in a statement.

Another 15 servicemen were wounded as government positions around the conflict zone came under repeated bombardment, the statement said.

A military spokesman told AFP that Ukrainian forces were also shelled heavily on Saturday morning at a village close to the government-held port city of Mariupol but did not sustain any casualties.

The mayor's office in Donetsk, the largest rebel-controlled city, said that two civilians were injured by shrapnel as shelling rocked the north of the city overnight.

An AFP journalist reported that the situation in the separatist industrial hub was however calm Saturday morning.

In neighbouring Lugansk region, where separatists control the main town, the Kiev-loyal local governor said rebels had shelled government-held areas 21 times over the last day.

Deadly fighting has rumbled on in the rustbelt east despite a two-month old ceasefire deal that has halted significant offensives, but failed to stop shelling at strategic flashpoints along the frontline.

Over 4,000 people -- mostly civilians -- have been killed in the conflict since April, the United Nations said.