Yemen: First medical evacuees leave Sanaa

The United Nations has opened an air bridge to evacuate the first of 30 patients and their care-givers from Yemen - a small but significant crack in a more than three-year-long blockade of civilian flights by a Saudi-led coalition backing Yemen's government in its war with the rebel Houthi movement.

Also in the programme: Democratic and Republican voters will choose their preferred nominees for the White House presidential race in the Iowa caucus; and Chinese artist Ai Weiwei discusses his latest work.

Image: A Yemeni child evacuated from Yemen on a UN aid flight. Credit: AFP / Getty Images.