SWEIMEH, Jordan — The son of Yemen’s assassinated former president emerged from seclusion in the United Arab Emirates on Tuesday and vowed to avenge “the blood of my father,” killed by Houthi rebels in Yemen the day before.

The son, Ahmed Ali Saleh, once a powerful military commander under the father, Ali Abdullah Saleh, made the pledge as warplanes from a Saudi-led coalition bombed Sana, the Yemeni capital, news reports said, striking targets including the Republican Palace.

The level of fighting on the streets of the city seemed lower than in preceding days, after the former president switched his allegiance from the Iranian-aligned Houthi rebels holding the capital to the Saudi-led forces seeking to expel them.

The move cost him his life, as Houthis turned their fury on him Monday for what they considered a betrayal. Although the precise sequence of events surrounding Mr. Saleh’s death remained unclear, a video broadcast by the rebels showed his body dumped in the back of a pickup truck.