According to the pro-Houthi Al Masirah broadcaster, more than 20 bodies of victims were transported to a military hospital.
A spokesperson for the Houthi Healthcare Ministry said that the airstrike targeted ambulance cars at the entrance of the hospital.
"The airstrikes were carried out on ambulance cars at the entrance to the Al Thawra hospital. All the victims were civilians," the spokesperson told the Al Jazeera broadcaster.
The Al Thawra hospital reportedly called on local residents to help those injured by donating blood.
On June 13, the Yemeni government forces, backed by the Saudi-led coalition, launched an offensive to seize the port of Hodeidah from the Shia Houthi rebels. The operation continues despite the UN warnings of a possible humanitarian catastrophe.
Yemen has been engulfed in an armed conflict between the government headed by President Abd Rabbuh Mansur Hadi and the Houthi movement for several years. The Saudi-led coalition of mostly Persian Gulf nations has been carrying out airstrikes against the Houthis at Hadi's request since March 2015.