Saudi-led air strikes on weapons caches in Yemen’s rebel-held capital have caused massive explosions that shattered windows, sent residents scrambling for shelter and killed a local TV presenter.

A TV station run by the rebels in Sana’a said 15 people were killed and dozens wounded in the bombing but those figures could not immediately be confirmed.

The explosions were the most powerful seen in the city since a Saudi-led air campaign against Iran-allied Shia rebels, known as Houthis, began last month. The blasts deposited a layer of soot on the top floors of residential buildings in Sana’a and left the streets littered with glass. Anti-aircraft fire rattled across the city in response.

Mushroom clouds rose over Fag Atan, in the mountainous outskirts of Sana’a, where the capital’s largest weapons caches are located. The site has been targeted several times in the Saudi-led air campaign, now in its fourth week.

A Yemeni official said the Saudi-led warplanes were demolishing parts of the mountain, hoping to uncover and destroy Scud missiles. About four miles away from Fag Atan, cars were damaged and charred, shop fronts were shattered and the windows were blown out of office buildings.

The Houthis’ TV network al-Masirah said 15 people died and that Mohammed Shamsan, a TV presenter for another network, was among those killed. It said members of his crew were wounded. Ambulances were rushing to the site of the explosions, and al-Masirah aired a statement by health authorities calling on citizens to donate blood.

Residents posted videos and pictures of the explosions, and the damage they had caused, on social media. “The hanging ceiling and chandelier fell because of the explosions,” one, Mohammed Mohsen, said.

Saudi Arabia and several of its allies, mainly Gulf Arab countries, launched the air strikes on 26 March, hoping to roll back the rebels, who seized Sana’a in September and have overrun large parts of the country with the help of security forces loyal to former President Ali Abdullah Saleh.

Western governments and Sunni Arab countries say the Houthis get arms from Iran. Iran and the rebels deny that, though the Islamic republic has provided political and humanitarian support to the group.

Rebel leader Abdul-Malek al-Houthi struck a defiant tone on Sunday, saying that “the great Yemeni people will never surrender and never be subjugated”.

Meanwhile, fighting intensified in the southern port city of Aden, where the Houthis and Saleh loyalists are battling youth militias and forces loyal to President Abed Rabbo Mansour Hadi, who fled the country last month in the face of the Houthi advance.

The Houthis and their allies have been trying to take over Aden for weeks. On Monday, heavy fighting broke out near the airport and in the central al-Arish district between the rebels and local armed groups formed by residents to defend their neighbourhoods, witnesses said.

Air strikes targeted a hotel in Aden suspected of being used by the Houthis and allied forces. There was no word on casualties.

In remarks published in his newspaper, Yemen Today, the ousted Saleh denied striking an alliance with the Houthis or that the rebels are in full control of the army. “We discussed the alliance after the Saudi assault on our country, and it has not materialised so far,” Saleh said.

He also pledged to “be positive” in dealing with a UN security council resolution adopted last Tuesday calling on Yemen’s rivals to end the violence and return to UN-led peace talks.

The security council resolution makes no mention of the Saudi-led air strikes but imposes an arms embargo on three leaders of the Shia rebel group, as well as on Saleh and his son. It also demands that the Houthis withdraw from areas they have seized, including Sana’a, and relinquish arms and missiles seized from military and security institutions.