Warplanes from a Saudi-led coalition launched air strikes on Monday against Yemen's Houthi militia positions in the north, centre and south of the country, residents said.
Saudi planes and artillery bombed the Iran-allied group's northern stronghold province of Saada, which borders the Kingdom, and air strikes hit suburbs of the southern port of Aden on the Arabian sea.
An Arab alliance has been bombing the fighters for more than two months in a bid to restore Yemen's exiled president Abd-Rabbu Mansour Hadi, currently in exile in Saudi Arabia, to power.
The Sunni Muslim states are also concerned that the Shi'ite rebels are a proxy for the influence of their arch rival Iran in impoverished Yemen.
The Houthis, who swept into Yemen's capital Sanaa in September and fanned out across the country, say they are winning a revolution against corrupt officials and hardline Sunni militants.
Air strikes pounded military positions aligned with the Houthis in Sanaa on Sunday, and residents reported the sounds of constant explosions and anti-aircraft fire continuing into Monday.
Warplanes dropped bombs on groups of Houthi fighters on the outskirts of Aden, a bastion of support for president Hadi and scene of heavy street fighting between the militiamen and local fighters for over two months.
