Saudi-led warplanes hit Yemeni rebels and their allies in Sanaa on Tuesday, in the first strikes on the rebel-held capital since the end of a five-day humanitarian truce, witnesses said.
The Saudi-led coalition resumed its bombing campaign early on Monday with raids on second city Aden, accusing the rebels of violating the temporary ceasefire which expired the previous night.
Tuesday's raids in the capital hit the presidential palace complex and several bases of troops loyal to ousted strongman Ali Abdullah Saleh, who is allied with the Shia rebels.
Witnesses said the targets included the Republican Guard missile brigade base of Fajj Attan, in south Sanaa, where previous strikes on April 20 set off a chain of explosions that killed 38 civilians.
Coalition aircraft also hit air defence and coastguard bases in Hodeida province on the Red Sea coast, witnesses said.
Residents also reported raids in the central province of Taez, and Daleh and Aden in the south.
The United Nations and aid agencies had pleaded for an extension of the ceasefire, the first pause in the bombing campaign the coalition launched on March 26 in a bid to restore the authority of exiled President Abedrabbo Mansour Hadi.
But coalition spokesman General Brigadier Ahmed al-Assiri charged on Monday that the rebels had abused the truce.
"They did not respect the humanitarian pause. That's why we do what is necessary to be done," he told AFP.