Warplanes from the Saudi-led coalition pounded Shia rebels across three Yemeni cities on Friday, as Riyadh reported the death of a Saudi child from cross-border fire.
The coalition has stepped up its raids on positions held by the Houthi Shia rebels and their allies since a humanitarian ceasefire ended late Tuesday.
The latest violence came as the UN's human rights agency said that at least 1,037 civilians have been killed in Yemen since the start of the air campaign on March 26.
Spokeswoman Cecile Pouilly said 234 children and 134 women were among the dead and that 2,453 others were wounded over the past eight weeks in a war that has heavily damaged infrastructure.
Huge explosions rocked the outskirts of the capital Sanaa after Friday's air strikes. There were also raids on second city Aden in the south and Marib province east of the capital, residents said.
"It was a morning of terror," one resident of a southern suburb of Sanaa told AFP after a wave of attacks on military bases in the Dhabwa and Rimat Hamid areas.
In north Sanaa, coalition warplanes targeted a stadium and a camp of the Republican Guards loyal to ousted president Ali Abdullah Saleh, who has sided with the Houthis.
In all, eight rebel and allied targets were hit in and around Sanaa, including Dalaimi air base near the international airport, witnesses said.
Residents said coalition raids also struck Houthi positions in Marib.
There were no immediate tolls available for Sanaa and Marib.
But in Aden, at least 16 Houthis and allied fighters were killed in raids and fighting on Friday, sources said, adding that three militiamen who back President Abedrabbo Mansour Hadi also died in clashes.
Hayef al-Bakri, a local militia official in the port city, urged the Saudi-led coalition to intervene on the ground in Aden "to save residents".
He told AFP that civilians in Aden were facing "abuses" at the hands of the rebels.
Across the border in Saudi Arabia, a mortar round fired from Yemen killed a Saudi child, a civil defence official in the Jazran region said.
Another three civilians were wounded, he added.
On Thursday, one civilian was killed and three wounded in cross-border shelling into Najran province, Saudi state television reported.
The coalition has said it was determined to pursue its air campaign against the Houthis in order to restore the authority of Hadi, who has fled to Riyadh with members of his government.
The United Nations, which has warned that Yemen is on the verge of total collapse, will host a conference next week in Geneva hoping to relaunch political talks on Yemen, despite uncertainty over who will attend.