Nato’s Supreme Allied Commander Europe Philip Breedlove said yesterday that the two-week-old ceasefire between Kiev and Ukraine’s separatist rebels was a “ceasefire in name only” as they sporadically exchanged fire over the weekend.

Gen Breedlove claimed to be hopeful about an agreement on Saturday to withdraw artillery to create a 10-mile buffer zone between Ukrainian government forces and fighters loyal to the self-proclaimed People’s Republic of Donetsk.

But he also accused Russia of enabling a free flow of weapons and fighters across the border which made it nearly impossible to determine how many of its troops were operating inside Ukraine.

And he said that it was clear that the number of Russian troops in Ukraine had declined significantly over the past week or so, “which is good, except that they haven’t returned home and are still available to bring their military force to bear on Ukraine, should it be desired.”

Kiev’s national security council spokesman Colonel Andriy Lysenko fell in line yesterday, announcing that ceasefire violations were obstructing fulfilment of the buffer zone plan.

“The first point is not being fulfilled so far, so we’re not talking about the other points,” he said.

Along with pulling back heavy weapons, the plan also calls for the withdrawal of foreign fighters and a ban on military flights over the combat area.

Col Lysenko said that resistance forces in eastern Ukraine had attacked Kiev military positions in 22 towns or villages on Saturday and that they had fired artillery at the airport in Donetsk.

Sporadic overnight shelling of the strategically vital city of Mariupol on the coast of the Sea of Azov was reported by the city council.

An official in Donetsk said that a shell of unknown origin had hit a munitions factory, causing a series of explosions.

Thousands of people marched through central Moscow yesterday to protest against the fighting in Ukraine and their government’s alleged complicity in it.

The demonstrators chanted slogans including “No to war” and “The junta is in the Kremlin, not Kiev,” suggesting support for the fascist-led coup that ousted democratically elected former Ukrainian president Viktor Yanukovych.