At least one blast struck the famed ancient quarter of Yemen's capital before dawn Friday, destroying centuries-old structures that had been considered jewels of traditional Islamic architecture.
The intricately crafted tower-houses of Sana's Old City, adorned with fanciful geometric patterns, are a UNESCO world heritage site. The cultural agency expressed deep dismay over the destruction of at least five of them.
At least six people were killed, with women and children among the injured, Yemeni officials said.
An 11-week-old Saudi-led air offensive in Yemen, targeting Shiite Muslim Houthi rebels, has killed more than 2,200 people, displaced about 1 million, and left 80% of the country's 25 million people in need of aid, according to international organizations.
Yemen's Houthi-run news agency blamed the Saudi-led coalition for the campaign's first direct strike on Sana's old Qasimi quarter. However, the chief Saudi military spokesman, Brig. Gen. Ahmed Asiri, denied that the coalition had bombed the Old City, the Saudi-owned news channel Al Arabiya reported and suggested that a rebel arms dump might have blown up.
"Residential buildings there are not suitable for storing weapons, and that is probably why the explosion occurred," he said.
The airstrikes, whose stated aim is to restore to power exiled President Abdu Rabu Mansour Hadi, have caused vast destruction in what was already the Arab world's poorest country. However, the attacks have failed to dislodge the Houthis from the capital or the strategic southern port city of Aden. Hadi, who fled Yemen in March, is in Saudi Arabia.
Saudi Arabia, the region's main Sunni Muslim power, views the Houthi insurgency as inspired by the Saudis' Shiite rival, Iran. The Tehran government denies arming the rebels and has bitterly denounced the air war, for which the United States has provided logistical support.
Sana fell to the Houthis nine months ago. Airstrikes in the capital have pounded bases and weapons caches belonging to the insurgents and their allies, often hitting nearby residential areas as well. Previous bombardment near the historic quarter had damaged some structures, but caused far less destruction than Friday's blasts.
Friday's destruction came two days before U.N.-brokered talks were to begin in Geneva aimed at halting the fighting, though officials indicated the start of indirect negotiations could be delayed by at least a day.
UNESCO's director-general, Irina Bokova, said she was "profoundly distressed" by the loss of life as well as "the images of these magnificent many-storied tower-houses and serene gardens reduced to rubble."
She called on all parties to the conflict to protect Yemen's historic and cultural sites, several of which had already been damaged. Those include the artifact-filled National Museum in Dhamar, which was flattened, according to UNESCO.
"This heritage bears the soul of the Yemeni people. It is a symbol of the millennial history of knowledge, and it belongs to all mankind," Bokova said.
The Old City has been inhabited for more than 2,500 years and was celebrated as a center of trade and the flowering of Islam.
Shaif Shareb, a government worker who lives in the quarter, was distraught.
"The airstrikes won't kill Houthis; this war is killing all Yemenis," he said.
Air raids Friday targeted Sana's Baqim district, killing at least 12 people, the Health Ministry said. Strikes also hit northern Saada province, a Houthi stronghold, including one reported to have come during Friday prayers, and ground fighting raged in several locales, including Aden and energy-rich Marib province.
Across Yemen, basic survival has become a daily struggle, with fuel, food and medical supplies low because of an air and sea blockade meant to prevent weapons from reaching the
Houthis. Access to healthcare has dwindled dramatically as hospitals close because power outages and lack of supplies and sanitation, and children in particular are threatened by outbreaks of disease.
Special correspondent Al-Alayaa reported from Sana and Times staff writer King from Cairo. Special correspondent Amro Hassan in Cairo contributed to this report.