Yemen's national airline said on Sunday it still lacks the security permits needed to resume commercial flights, a day after the transport minister said some flights would be allowed as a nationwide blockade is eased.
"I was sitting at home and heard the first strike hit the ministry of defence".
"My entire house shook", said Aatif, who fled with his family from the neighbourhood.
Witnesses said the number of casualties may rise as wounded are pulled from the rubble.
Two air strikes targeted the ministry late on Friday and plumes of smoke could be seen billowing from the building, the rebel media network Al Masirah quoted witnesses as saying.
Mohammad Ali al-Houthi said that if Saudi Arabia target Hodeidah port and its coastal areas, "we will make unprecedented steps" against the country, the Arabic-language Al Mayadeen TV network reported.
The Houthis have fired more than 70 missiles into Saudi Arabia in the past two years, but the Riyadh attack was the deepest into Saudi territory.
Saudi Arabia has blamed Iran for supplying the rebels with the missile, sparking tensions between the Middle East rivals and fears of a military confrontation.
This week, UN aid chief Mark Lowcock warned the Security Council (UNSC) that Yemen would face "the largest starvation the world has seen for many decades, with millions of victims", unless the blockade was lifted.
More than 2,000 Yemenis have died in a cholera outbreak now affecting almost one million people.
The Houthis, fighters drawn mainly from Yemen's Zaidi Shia minority and allied to long-serving former president Ali Abdullah Saleh, control much of Yemen including the capital San'aa.
The conflict has left more than 8,650 people dead, including many civilians.