Ceasefire takes hold in Ukraine

A UN-backed ceasefire showed signs of taking hold in Ukraine on Wednesday, but tensions remained high after the US accused Russia of "lies" and Britain ordered a small troop deployment to train Kiev's forces.

Russia in turn has warned it could cut off gas supplies to Ukraine by the weekend -- and, by extension, to parts of the European Union.

For the first time since the European-brokered truce was imposed February 15, no deaths were reported in Ukraine's war zone by either side for the past 24 hours.

Rebels insisted they were withdrawing artillery, rocket launchers and tanks from some areas, and journalists saw a column of howitzer guns being driven along a road near the separatist stronghold of Donestk.

Kiev says it will not carry out an arms pull-back until a full and "comprehensive" ceasefire is observed and has accused Russia of continuing to send military hardware in to bolster the rebels.

US Secretary of State John Kerry on Tuesday launched his most scathing accusation to date over Russia's alleged involvement in the conflict.