Kiev - Fighting in east Ukraine over the last 24 hours has killed at least nine soldiers and wounded 29, the military said Tuesday, as rebels fought to secure more territory in the war zone.
The focus of the fighting remained the area around the city of Debaltseve, located halfway between the rebel strongholds of Donetsk and Lugansk and where the pro-Russian separatists have launched attacks.
Ukraine's military said the rebels had fired 120 times at its positions over the past day.
"Nine soldiers were killed and 29 injured in the (war zone) during the last 24 hours," military spokesman Vladyslav Seleznyov said.
Clashes have intensified as a September truce has unravelled, with the main rebel leader in the Donetsk region last week announcing he would no longer take part in peace talks and planned to seize more territory.
International concern has mounted over the conflict and Russia has faced pressure to rein in the separatists it is accused of arming and backing with troops. Moscow firmly denies the accusations.
A rocket attack on a residential area in the strategic port city of Mariupol that killed 30 people at the weekend has drawn particular worry.
Rebels distanced themselves from the attack in Mariupol, the last major city in the country's two separatist provinces still controlled by Kiev and located away from the immediate front line.
However, a senior UN official told an emergency Security Council meeting on Monday that the deadly rocket barrage came from rebel-controlled territory and deliberately targeted civilians, in violation of international humanitarian law.
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"Mariupol lies outside of the immediate conflict zone. The conclusion can thus be drawn that the entity which fired these rockets knowingly targeted a civilian population," UN Under Secretary-General Jeffrey Feltman said.
"We must all send an unequivocal message: The perpetrators must be held accountable and brought to justice."
Russian President Vladimir Putin has remained defiant in the face of calls to rein in the rebels he is accused of backing.
On a visit to Saint Petersburg on Monday, he branded the Ukrainian army NATO's "foreign legion" whose objective was to contain Russia.
He also claimed Ukrainian men wanted to flee to Russia because they did not want to become "cannon fodder" in an army that he described as mostly "volunteer nationalist battalions".
NATO head Jens Stoltenberg later dismissed the comments as "nonsense".
Russia, whose economy is slowing because of a plunge in the price of its oil exports and pressure put on companies by Western sanctions over Ukraine, was stripped of its investment-grade credit rating by Standard and Poor's on Monday.