– Saudi pledge –
Egyptian President Abdel Fattah al Sisi told fellow leaders the region faced “unprecedented” threats.
And Saudi King Salman vowed that the air strikes would continue until they bring “security” to the Yemeni people.
But UN Secretary General Ban Ki moon urged Arab leaders to “lay down clear guidelines to peacefully resolve the crisis in Yemen”.
Saudi warships evacuated dozens of foreign diplomats from Aden hours before the kingdom launched the air strikes on the advancing rebels, state television said on Saturday.
Riyadh has vowed to do “whatever it takes” to prevent Hadi’s overthrow.
But experts say the Saudis will be reluctant to send in ground troops for fear of getting bogged down in a protracted conflict.
The Huthis are backed by army units loyal to former president Ali Abdullah Saleh, who stepped down in 2012 after a year-long popular uprising and is accused of supporting the rebels.
In a televised speech Saturday, Saleh urged the Arab League to help end the crisis “peacefully”, saying the “problem will not be solved with strikes”.
Gulf diplomats said the bombing could last up to six months, and accused Iran of providing “logistical and military support” to the rebels.
“According to estimates, there are 5,000 Iranians, (members of the pro-Tehran Lebanese movement) Hezbollah and Iraqi militia on the ground in Yemen,” said one Gulf official, who did not want to be named.
It was not possible to independently verify the claim.
The Gulf officials said Riyadh and its allies had decided to intervene after satellite imagery in late January showed the movement of Scud missiles north towards the Saudi border, with the capacity to strike a large part of the kingdom’s territory.
A coalition spokesman told reporters Saturday that “most” of the Huthis’ missile capabilities were believed to have been destroyed in the air strikes.