Saudi-led coalition warplanes bombed Yemeni rebel targets including in the capital on Thursday following insurgent drone strikes on a key oil pipeline that Riyadh said were ordered by its arch-rival Tehran.
The new bombardment came after the UN envoy, who has been spearheading efforts to end more than four years of conflict in the Arab world's poorest country, warned it still faced the threat of plunging into all-out war.
The Saudi deputy defence minister warned that Tuesday's attack by Yemeni rebels on a major pipeline in the kingdom was "tightening the noose" around peace efforts.
A coalition statement carried by Saudi-owned Al Arabiya TV, said the Sunni Muslim alliance struck military bases and facilities and weapons storage sites with the aim of “neutralizing the ability of the Houthi militia to carry out acts of aggression”.
“The sorties achieved its goals with full precision,” the coalition said. It had urged civilians to avoid those targets.
One resident reported a strike near a densely-populated district, where flames and clouds of smoke could be seen. A car was half-buried under rubble and twisted metal on a street lined with bystanders.
“There was an air strike near us, in the middle of an area packed with residents between Hael and Raqas (streets),” Abdulrazaq Mohammed told Reuters. “The explosion was so strong that stones were flying. This is the first time our house shakes so much.”
The rebels' Al-Masirahn television said the caolition carried out at least 19 strikes, 11 of them in the capital.
A strike on one Sanaa neighbourhood killed at least six people and wounded 10, Dr Mokhtar Mohammed of the capital's Republic Hospital said.
An AFP correspondent saw one residential building that had been reduced to rubble by an air strike. Residents were using their bare hands in a desperate search for survivors.
The raids began around 8 am (0500 GMT) while many Yemenis were asleep awaiting the end at sunset of the daytime fast observed by Muslims during the holy month of Ramadan, a witness told AFP
"There were many strikes," he added.
Sanaa has been held by the Houthi movement since it ousted the internationally recognized government of Abd-Rabbu Mansour Hadi from power there in late 2014.
The coalition has previously targeted suspected drone and missile storage sites in the city.
The Houthis said they were responsible for the attack on the Saudi pipeline which did not disrupt oil output or exports, claiming that it was a response to "crimes" committed by Riyadh during its bloody air war in Yemen.
The drone strikes further raised tensions in the region after the mysterious sabotage of several oil tankers and the US deployment of an aircraft carrier strike group and B-52 bombers to the Gulf over alleged threats from Iran.
'Tightening Noose' On Peace
Saudi Arabia’s deputy defense minister on Thursday accused Iran of ordering Tuesday’s armed drone attack on two oil pumping stations in the kingdom.
“The terrorist acts, ordered by the regime in Tehran and carried out by the Houthis, are tightening the noose around the ongoing political efforts,” Prince Khalid bin Salman tweeted.
"The attack by the Iranian-backed Houthi militias against the two Aramco pumping stations proves that these militias are merely a tool that Iran's regime uses to implement its expansionist agenda in the region," the prince said on Twitter.
The Saudi state minister for foreign affairs, Adel al-Jubeir, charged that the Houthis were "sacrificing the need of the Yemeni people for the benefit of Iran".
The group denies being a puppet of Tehran or receiving arms from Iran, anod says its revolution is against corruption.
The head of the Houthis’ Supreme Revolutionary Committee, Mohammed Ali al-Houthi, said Iran did not direct the strike and that the movement manufactures its drones “locally”. Tehran also denies providing the group with arms.
We are not agents of Iran...we took this decision by ourselves,” al-Houthi told the BBC. “
The coalition described the drone attack as a “war crime”.
Key ally the United Arab Emirates warned of reprisals.
"We will retaliate and we will retaliate hard when we see Houthis hitting civilian targets like what happened in Saudi Arabia," the UAE minister of state for foreign affairs, Anwar Gargash, said on Wednesday.
Saudi Arabia and its allies intervened in Yemen when President Abd-Rabbu Mansour Hadifled into Saudi exile as the rebels closed in on his last refuge in Yemen's second city Aden after sweeping through most of the rest of the country.
The intervention has retaken much of the south but the capital and most of the populous central highlands remain in rebel hands.
A grinding war of attrition has set in with third city Taiz and the vital Red Sea aid port of Hodeida turned into battlegrounds.
In December, UN mediators brokered hard-won truce deals for both cities during talks in Sweden but the hoped for momentum for talks on a comprehensive peace has failed to materialise.
On Tuesday, UN observers confirmed that rebel fighters had pulled out of Hodeida and two other Red Sea ports, unilaterally carrying out a key redeployment that was supposed to follow the December ceasefire.
UN envoy Martin Griffiths welcomed the pullback, but warned the Security Council on Wednesday that the risks of a slide into all-out war remained high.
"There are signs of hope," he said, but there are also "alarming signs" of war.
The Sanaa air strikes and renewed fighting in Yemen’s Hodeidah port that breached a UN-sponsored truce in the Red Sea city, could complicate peace efforts to end the four-year war that has killed tens of thousands of people, many of them civilians.
The UN describes the war as the world's worst humanitarian crisis, with 24.1 million -- more than two-thirds of the population -- in need of aid.