More than 20 air strikes by Arab forces hit targets controlled by Houthi rebels across Yemen late on Sunday, residents said.
An Arab military coalition has been bombing the Houthis for three months to restore the country's exiled government and fend off what they see as Iranian influence.
The Houthis took over the capital Sanaa in September and spread throughout the country in a push they view as a revolution against a corrupt government but deny any military links with their allies in Tehran.
Backed up by Arab bombings and weapons drops, local fighters in Yemen's south and its main city Aden have resisted the heavily armed militia's advance.
In Aden, residents reported three raids on the Houthi-controled international airport while another bombing destroyed parts of the Ottoman-era Seera castle, a symbol of the city and the latest cultural site in Yemen to suffer damage in the war.
Along Yemen's border with Saudi Arabia, residents in Hajja province reported five air raids on buildings housing Houthi forces and their army allies, who have repeatedly clashed with Saudi forces in recent weeks.
Mainly drawn from the Shi'ite Zaydi sect, the Houthis are allied to Yemen's former president Ali Abdullah Saleh, who still has the loyalty of much of the army. They are fighting President Abd-Rabbu Mansour Hadi, who is exiled in Riyadh, and southern separatists, tribal factions and other political groups.
