The UN on Tuesday urged the Saudi-led coalition to end a blockade which has halted the flow of humanitarian supplies into Yemen, further threatening some seven million people facing famine-like conditions. 

"If these channels, these lifelines, are not kept open it is catastrophic for people who are already in what we have already called the world's worst humanitarian crisis," a spokesman for the United Nations humanitarian office, Jens Laerke, told reporters in Geneva.