KIEV (Reuters) - Two Ukrainian soldiers have been killed and twenty wounded in the past 24 hours, the Ukrainian military said on Monday, describing near-constant shelling by pro-Russian rebels in certain parts of separatist eastern territories.

The ceasefire brokered in Minsk, Belarus, four months ago has stemmed large-scale fighting, but skirmishes claim lives almost daily on both sides. International monitors have warned of the threat of a bigger flare-up.

“The situation in the conflict zone is deteriorating. At key parts of the frontline heavy weapons continue to shell our positions almost incessantly,” Ukrainian military spokesman Andriy Lysenko said in a televised briefing.

He accused separatists of opening fire in areas that had previously been relatively peaceful and said the fighting showed signs of spreading further.

A map provided by the Ukrainian military to illustrate recent separatist activity depicted attacks along almost the entire length of the frontline.

Separatist officials accused Ukrainian forces of shelling residential areas of rebel-controlled Donetsk city, wounding ten civilians, rebel press service DAN reported.