A Saudi-led coalition bombarded militant positions early Wednesday in Yemen's main southern city Aden in a seventh night of raids that also targeted the capital and other areas.
In Aden, the strikes were focused on the militant-held provincial administration complex in Dar Saad in the north of the city, according to a military official.
He said there were "many dead and wounded" among the Houthi Shia militants but was unable to give a precise toll.
The coalition has vowed to keep targeting the Houthis and allied army units loyal to former strongman Ali Abdullah Saleh until they end their insurrection.
Iran is also accused of backing the Houthis but Tehran denies providing military support.
The headquarters of a renegade army brigade loyal to Saleh was targeted overnight in the north of Aden, as well as the city's international airport, the military official said.
Militia fighters loyal to President Abedrabbo Mansour Hadi have captured 26 Houthis during the fighting in Aden, one of their leaders said.
In the western port city of Hodeida, four civilians were killed and 10 injured when a dairy was hit in the night, said medical sources.
The circumstances of the bombing were unclear, with some witnesses saying the dairy was hit by a coalition air strike and others blaming pro-Saleh forces.
Six other civilians were killed in an air raid targeting Maydi in the northwest province of Hajjah, according to medical sources.
Coalition planes also targeted camps of the Republican Guard, which is loyal to Saleh, around Sanaa and in the central region of Ibb overnight, according to residents.
Several Houthi positions were also targeted in the northern rebel strongholds of Hajjah and Saada.
After entering the capital in September, the Houthis and their allies gradually conquered areas in the centre, west and south before bearing down on Aden last month, prompting Hadi to flee to Saudi Arabia.
The UN said Tuesday that at least 93 civilians had been killed and 364 injured since the nearly week-old Saudi-led air campaign began.