From Press TV:

Russia is warning that the Saudi-led coalition might soon attack the Red Sea port city of Al Hudaydah. The city is currently held by Houthi rebels and is needed to receive humanitarian aid into the country. If the city is attacked, it could make the humanitarian situation in Yemen even worse than it already is.

Battles in the area “would not only inevitably lead to a mass exodus of the [local] population but would also de facto cut the [Yemeni] capital of Sana’a from… food and humanitarian aid supplies.”