A Russian armoured column bore down on Ukraine's capital Kyiv on Tuesday after the deadly shelling of civilian areas in its second-largest city indicated that frustrated Russian commanders could resort to more devastating tactics to achieve the goals of their invasion.

Nearly a week since Moscow unleashed its war on its neighbour, its troops have failed to capture a single major Ukrainian city after running into fierce resistance.

But it still has more forces to throw into the fight even though Russian President Vladimir Putin faces worldwide condemnation and international sanctions for his actions...