A Saudi-led military coalition has been preparing an assault on Hodeidah, Reuters reported.
"The UN is concerned about the humanitarian repercussions of such an attack in terms of inflaming the humanitarian crisis even further, let alone our concerns about loss of civilian life were there to be a large-scale attack on port," Zeid told a news conference in Geneva.
Since March 25, 2015, Saudi Arabia and some of its Arab allies have been carrying out airstrikes against the Houthi Ansarullah movement in an attempt to restore power to resigned former president.
According to Yemen’s Legal Center of Rights and Development, the Saudi campaign has claimed the lives of over 12,000 Yemenis and left more than 20,000 others wounded.