Saudi-led warplanes pounded rebel positions in the Yemeni capital on Tuesday, an AFP correspondent said, reporting powerful explosions across Sanaa.
Witnesses said targets included the police academy and the headquarters of the security services, both in the heart of the capital which has been controlled by the Shia Houthi rebels since September last year.
Overnight strikes also hit the Sanaa residences of Houthi leaders, witnesses said.
The strikes followed reports that Gulf Arab members of the Saudi-led coalition had sent thousands of heavily armed reinforcements to Yemen after a Houthi missile attack killed 60 coalition soldiers on Friday.
The additional troops, most of them from Qatar and Saudi Arabia, were deployed to the battleground eastern oil province of Marib where the attack took place, the reports said.
The coalition launched its air war against the rebels when President Abd Rabbou Mansour Hadi fled to neighbouring Saudi Arabia in March after they entered his last refuge, Yemen's second city Aden.
After his loyalists recaptured the southern port city in July, the coalition launched a ground operation which has seen the rebels pushed back from five southern provinces, although they still control the capital Sanaa and much of the north and centre.