Saudi-led coalition warplanes bombed rebel camps in Yemen for a second day on Friday, as President Barack Obama said the United States shared a "collective goal" with its regional ally to see stability in the war-torn state.
Obama offered support to Saudi ruler King Salman in a phone conversation as it emerged the US military had rescued two Saudi pilots forced to eject from their fighter jet in the region on Thursday.
A months-long rebellion by Shiite fighters in Yemen has escalated into a regional conflict that threatens to tear apart the impoverished state at the southern tip of the Arabian Peninsula.
Amid the air raids and scattered fighting, a call for a ceasefire was issued by former president Ali Abdullah Saleh, suspected of being allied with the rebels.
Twelve died when residential areas were hit in a raid on a military base north of the capital, the officials told AFP.
Warplanes also bombed a Huthi-controlled army brigade in Amran province north of Sanaa, and arms depots in the northern rebel stronghold of Saada, residents said.
The rebels have also clashed with Sunni tribes as they push south. At least 21 were killed on Friday when tribesmen ambushed their vehicles north of Aden, a local official said.
Arab League Summit
He travelled from Riyadh after making his way from Aden as the rebels advanced on the city.
Saudi Arabia has reportedly also mobilised 150,000 troops near the border.
The coalition said all members had contributed to the operation, with UAE warplanes "intensively" participating in the strikes.
The coalition now completely dominates Yemen's airspace, and aircraft seized by the Huthis have been destroyed, spokesman General Ahmed Assiri said in Riyadh.
Iran has reacted furiously to the air strikes, calling them a violation of Yemen's sovereignty.
"Any military action against an independent country is wrong and will only result in a deepening crisis and more deaths among innocents," Foreign Minister Mohammad Javad Zarif said.
The conflict has raised a major hurdle to Washington's longstanding drone war against Al-Qaeda militants who have exploited the power vacuum since Saleh's downfall in 2012.
Barack Obama Support
The White House said Obama had offered US support to King Salman during a call with the Saudi ruler, saying the United States shared a "collective goal" with the kingdom to see stability in Yemen.
"The president reaffirmed the strong friendship between the United States and Saudi Arabia and emphasised the United States' support for the action taken by Saudi Arabia, Gulf Cooperation Council members, and others in response to President Hadi's request and in support of the legitimate government of Yemen," said National Security Council spokeswoman Bernadette Meehan.
King Salman, meanwhile, thanked the US for rescuing two Saudi pilots who ejected off Yemen's coast in international waters.
Washington has pledged logistical and intelligence support for the Saudi-led campaign.
The Islamic State (IS) group, which has seized vast tracts of territory in Syria and Iraq, is also vying with Yemen-based Al-Qaeda in the Arabian Peninsula (AQAP).
Some observers warn that the Saudi strikes risk feeding instability and extremism.
"I think the net effect of this operation is ultimately dangerous for Yemen's future path," said Frederic Wehrey, at the US-based Carnegie Endowment for International Peace.
"It will open up more fissures on the ground, perhaps bolster the Huthis' popular support as defenders of Yemeni sovereignty, and create more opportunities for AQAP and IS to flourish."
Hassan Nasrallah, chief of Lebanon's pro-Iran movement Hezbollah, said in a speech that Saudi Arabia will be roundly defeated and called for a political settlement.
"Otherwise, defeat and shame will meet the invaders," he warned.
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