"The process of recovering the bodies is finished now. The corpses of 36 workers, many of them burnt or in pieces, were pulled out after an air strike hit the plant this morning," resident Issa Ahmed told Reuters by phone from the site.
Saudi Arabia, leading a coalition of nine Arab states, began carrying out airstrikes in the neighboring Yemen on 26 March 2015, in a bid to restore power to exiled President Abd-Rabbu Mansour Hadi.
The Saudi-led intervention has come under fire from human rights groups for not protecting civilians and causing widespread destruction. UK-based Amnesty International said in a report this month that the campaign had left a "bloody trail of civilian death" which could amount to war crimes.
Air raids killed 65 people in the front-line city of Taiz last Friday, most of them civilians, and the bombing of a milk factory in Western Yemen in July killed 65 people including 10 children.
Over 4,300 people have been killed in five months of war in Yemen while disease and suffering in the already impoverished country have spread.