Military alliance battling Houthis says it targeted several air defence sites and ballistic missile depots in Sanaa.

Yemen‘s capital, Sanaa, has been rocked by powerful explosions following air raids by a military coalition led by Saudi Arabia and the United Arab Emirates which is fighting the country’s Houthi rebels.

Also on Saturday, the Houthis claimed to have carried out drone attacks on military targets in the King Khalid air base in southwestern Saudi Arabia.

According to Houthi spokesman Yahya Sarei, the drone attacks targeted radars and military positions at the air base near the city of Khamis Mushait. There was no comment from the Saudi-UAE coalition on the rebel claim.

The Saudi-UAE air attacks in Sanaa followed the coalition’s start of a military operation aimed at what it called “legitimate” rebel targets in the capital, held by the Houthis since 2014.

Residents reported seeing flames rising from rebel military camps in different parts of the city.

There was no word on casualties.

According to the coalition’s spokesman Colonel Turki al-Maliki, the strikes targeted five rebel air defence sites and a ballistic missile depot in Sanaa.

“The alliance command is committed to preventing the terrorist Houthi militia and other terrorist organisations from having access to such military capabilities,” he added, according to Saudi state news agency SPA.

‘Hundreds of times’

Speaking from Sanaa, Al Jazeera’s correspondent Mohammed al-Attab said Yemeni civilians had become accustomed to such air attacks.

“The attacks do not make any difference to the Houthis or to the Yemenis because these kinds of military camps have already been destroyed,” he said.

These kinds of targets, he added, have been attacked “hundreds of times” by Saudi fighter jets for over four years.

“The Houthis are now using guerilla war tactics near the Saudi border,” al-Attab said. “So it doesn’t make any difference [to them] when Saudi Arabia calls its current military campaign as wide-scale air strikes.”

The latest attacks come as the United Nations‘ special envoy to Yemen, Martin Griffiths, is trying to break a stalemate in the peace process for the impoverished country.

Yemen has been in the grip of a devastating power struggle between the Saudi-backed government and the Houthis since late 2014.

The conflict has intensified since 2015 when the Houthis advanced on the government’s temporary capital of Aden, prompting Saudi Arabia and its allies to start a military campaign against the group.

The Saudis fear that the Houthis will give their regional rival, Iran, a strategic foothold in the Arabian Peninsula.