Houthis rallied in Yemen's capital on 26 March as warplanes from Saudi Arabia and Arab allies struck at the Houthi militia forces who have taken over much of the country in their campaign to oust President Abd Rabbuh Mansour Hadi.

The Saudi-led military intervention marks a major escalation of the Yemen crisis, in which Iran supports the Shi'ite Muslim Houthis, and Sunni Muslim monarchies in the Gulf back Hadi and his fellow Sunni loyalists in Yemen's south.

Iran denounced the surprise assault on the Houthis and demanded an immediate halt to Saudi-led military operations.

It emerged during Thursday that Hadi had left his last refuge in Yemen, the southern port city of Aden and travelled to Saudi Arabia.

Saudi-owned al Arabiya television said he would go onto the Egyptian Red Sea resort of Sharm el-Sheikh to attend an Arab summit on 28 March. But it was not certain if Hadi would be able to return to Aden.

On the city's northern outskirts, Houthis and allied troops fought gun battles with militiamen loyal to Hadi. Thirteen pro-Houthi fighters and three militiamen were killed. Pro-Hadi fighters retook Aden airport, a day after it was captured by Houthi forces advancing on the city.