Ukrainian rebels mobilise as fighting escalates

Ukraine has accused Russian-backed separatists of trying to provoke a wider conflict, after a Ukrainian soldier was killed by shellfire in the Donbas region. Meanwhile the US Vice President Kamala Harris says Russia's aggression is threatening the foundation of European security -- but it will face severe costs if it invades Ukraine. Also in this programme: We meet the teenager making tens of thousands of dollars from digital art; and what's the secret to Norway's winning ways at the Winter Olympics? (Photo: Thousands of Russian troops have been taking part in joint military exercises in Belarus, which borders Ukraine. Credit: EPA/Russian Defence Ministry)