Despite the ceasefire which began at midnight local time on Sunday (2200 UTC), both the Ukrainian military as well as the separatist rebels were trading accusations of shelling within hours.

Ukrainian forces said the ceasefire was being observed "generally," but claimed they had been fired at 10 times overnight.

Although no incidents were reported after 3 a.m., the military also accused rebels of still trying to occupy the village of Chornuhine around the key strategic government-held town of Debaltseve, where the pro-Russian rebels battled fiercely to surround Ukrainian forces in the hours leading up to the truce.

According to AFP news agency, two civilians were also killed in the reported overnight rocket fire. The missiles reportedly came from an area of Kyiv under command of a renegade group of Cossack fighters, who insist they will not obey rebel chief demands to the latest Minsk ceasefire.

"An elderly man and woman died after Grad missile fire hit the town of Popasna in the Lugansk region some 20 minutes after the truce came into force at 2200 GMT (UTC) Saturday," local governor Gennadiy Moskal reportedly said.

'Difficult peaceful process'

Ukrainian President Petro Poroshenko issued the ceasefire order for all the country's armed forces to hold their fire in a live broadcast.

"I very much hope that the last chance to begin the long and difficult peaceful process for a political settlement will not be wasted," Poroshenko said.

Cessation of hostilities is only the first point in a series of planned steps which were agreed in Belarus last week in talks promoted by Germany and France.

Withdrawal of heavy weaponry from the front line, creating a zone roughly 50-140 kilometers (30-85 miles) wide is to begin Monday and be completed in two weeks. There are no provisions for the withdrawal of troops.

The peace plan also requires the Ukrainian government to resume paying pensions and state benefits to citizens in rebel-held territory.

kb/rc (Reuters, AFP, AP)