Arab warplanes pounded Iranian-backed rebels in Yemen for a third night while President Abedrabbo Mansour Hadi held summit talks in Egypt Saturday with regional allies seeking to prevent his overthrow.
The deeply tribal and impoverished Arabian Peninsula state, on the front line of the US battle against Al-Qaeda, is the scene of the latest emerging proxy struggle between Middle East powers.
An Arab coalition, led by Saudi Arabia and other Sunni-ruled Gulf monarchies, is battling to avoid having a pro-Iran regime on its doorstep, as Shiite Huthi rebels tighten the noose around Hadi's southern stronghold.
Air strikes against the rebels could last up to six months, Gulf diplomatic officials said, voicing fears that they could face retaliation at home by Iran.
Heavy strikes shook the rebel-held capital Sanaa for a third consecutive night until dawn on Saturday, residents said.
"It was an intense night of bombing and the windows shook," said a foreigner working for an international aid organisation in Sanaa.
"People want to leave but there are no flights out of Yemen," she said.
According to an AFP photographer, it was the most violent night of raids heard in the capital since the Saudi-led operation began.
He said the bombing was felt throughout the night until dawn.
The air strikes apparently mainly targeted arms depots and other military facilities outside Sanaa, witnesses said.
Saudi Arabia says more than 10 countries have joined the Arab coalition defending Hadi, who arrived in Egypt on Friday to join allies at a weekend summit, a day after he surfaced in Riyadh.
He went into hiding earlier in the week as rebel forces bore down on his refuge in the main southern city of Aden and a warplane attacked the presidential palace.
- 'Unprecedented' threats -
The Arab summit, which opened Saturday in the Egyptian resort of Sharm el-Sheikh, is expected to back the offensive against the rebels and approve the creation of a joint military force to tackle extremists.
Egyptian President Abdel Fattah al-Sisi told fellow Arab leaders the region faced "unprecedented" threats.
Saudi Arabia's King Salman vowed that the military intervention his government is leading would continue until it brings "security" to the Yemeni people.
The situation has become increasingly tense in Aden with rebel forces clashing with anti-Huthi militiamen in several areas, raising fears that Hadi's last bastion could fall.
On Friday, at least eight people were killed in fighting around the city's international airport.
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Saudi warships evacuated dozens of foreign diplomats from Aden hours before the kingdom launched air strikes on the advancing rebels, state television said Saturday.
The official SPA news agency said that 86 people had been pulled out on Wednesday.
It was only announced after their arrival at a Saudi naval base in Jeddah on Saturday aboard two vessels.
Saudi Arabia has vowed to do "whatever it takes" to prevent Hadi's overthrow, accusing Shiite Iran of backing the attempted takeover by the Huthi rebels, who have seized swathes of the country.
Hadi called for the Saudi-led military intervention to continue until Shiite Huthi rebels surrender and their leaders are brought to justice.
"I call for this operation to continue until this gang surrenders and withdraws from all locations it has occupied in every province," he told an the summit.
But experts say the kingdom will be reluctant to send in ground troops for fear of getting bogged down in a protracted conflict.
- US support -
US President Barack Obama said Washington shared a "collective goal" with its regional ally to see stability in Yemen.
Obama offered support to King Salman in a phone conversation as it emerged the US military had rescued two Saudi pilots forced to eject from their fighter jet over the sea off Yemen after a technical problem.
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.
Dozens of civilians are reported to have been killed in Saudi-led Operation Decisive Storm against the Huthis and their allies.
An army unit loyal to Saleh, along with Shiite militiamen, captured two towns in Abyan province to the east of Aden, military sources said.
The rebels have also clashed with Sunni tribes as they push south.
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.
Washington has pledged logistical and intelligence support for the Saudi-led campaign.