At least two Saudi soldiers have been killed in the latest fighting, and the conflict is further raising tensions in the region, with Iran warning Saudi Arabia not to interfere in Yemen's internal affairs.
Ali Larijani, the speaker of the Iranian parliament, said on Sunday: "The intervention of Saudi government in Yemen and repeated bombardment of unprotected Yemeni Muslims by Tornado and F-15 fighters is astounding.
"How has his Excellency, the servant of the two honourable shrines, allowed Muslims' blood be split in Yemen by means of its military devices? The news proves that the US government has been the accomplice and assistance in such suppressive measures."
The Iranian parliament also called on the Organisation of the Islamic Conference to intervene to stop the killing of Yemeni Muslims.
Hashem Ahelbarra reports from Sana'a, the Yemeni capital, where he's been gauging the fallout from this ongoing battle.