A charity has warned that millions of Yemenis are edging closer to famine and fatal disease one year after a Saudi-led coalition imposed a blockade on sea, land and air routes into the Arab world’s poorest country.

Jan Egeland of the Norwegian Refugee Council said “the past 12 months have been a never-ending nightmare for Yemeni civilians”.

The Saudi-led coalition fighting Iran-backed Shia Houthi rebels had restricted access to Yemen in November last year after a missile assault by rebels targeted the Saudi capital, Riyadh.

Malnourished childrenThe war has been ongoing since 2015 (AP)

The coalition has been at war with the Houthis since March 2015 in a conflict that has generated the world’s worst humanitarian crisis.

The Norwegian charity said the war has left 12 million people at imminent risk of descending into famine.