A Saudi-led coalition fighting Iran-backed Houthi rebels in Yemen unleashed a barrage of airstrikes on the capital and a strategic Red Sea city, officials said on Saturday. At least eight people were killed.

The overnight airstrikes on Sanaa and Hodeida both held by the Houthis came a day after the rebels attacked an oil depot in the Saudi city of Jeddah, their highest-profile assault yet on the kingdom.

Brig Gen Turki al-Malki, a spokesperson for the Saudi-led coalition, said the strikes targeted sources of threat to Saudi Arabia, according to the state-run Saudi Press Agency or SPA.

He said the coalition intercepted and destroyed two explosives-laden drones early on Saturday. He said the drones were launched from Houthi-held civilian oil facilities in Hodeida, urging civilians to stay away from oil facilities in the city.

Footage circulated online showed flames and plumes of smoke over Sanaa and Hodeida.

Associated Press journalists in the Yemeni capital heard loud explosions that rattled residential buildings there.

The Houthis said the coalition airstrikes hit a power plant, a fuel supply station and the state-run social insurance office in the capital.

A Houthi media office claimed an airstrike hit houses for guards of the social insurance office in Sanaa's Haddah neighbourhood, killing at least eight people and wounding four others, including women and children.

The office shared images it said were from the aftermath of the airstrike. It showed wreckage in the courtyard of a social insurance office with the shattered windows of a nearby multiple-story building.

Hamoud Abbad, a local official with the Houthis in Sanaa, said the facility is located close to a building used by the UN agencies in the capital. He claimed that UN vehicles were seen leaving the area prior the airstrikes.

In Hodeida, the Houthi media office said the coalition hit oil facilities in violation of a 2018 cease-fire deal that ended months of fighting in Hodeida, which handles about 70 per cent of Yemen's commercial and humanitarian imports. The strikes also hit the nearby Port Salif, also on the Red Sea.

Al-Malki, the coalition spokesperson, said it targeted drones being prepared in Hodeida to be launched on the kingdom. He accused the Houthis of using civilian infrastructure, such as Hodeida's ports and the Sanaa airport, to launch attacks on Saudi oil facilities, according to SPA.

A UN mission overseeing the Hodeida deal voiced concern about the airstrikes and urged warring sides to maintain the civilian nature of the ports and avoid damage to civilian infrastructure.

The escalation, which comes on the seventh anniversary of the Saudi-led coalition's intervention in Yemen's war, is likely to complicate efforts by the UN special envoy for Yemen, Hans Grundberg, to reach a humanitarian truce during the holy month of Ramazan in early April.

It comes as the Gulf Cooperation Council plans to host the warring sides for talks late this month. The Houthis, however, have rejected Riyadh the Saudi capital where the GCC is headquartered as a venue for talks, which are expected to include an array of Yemeni factions.

Once again we are seeing civilians bearing the brunt of this conflict which is just getting worse every year, said Erin Hutchinson, Yemen director at the Norwegian Refugee Council, a charity working in Yemen. This escalation is going to do nothing to elevate the hardships that millions are going through.

Yemen's brutal war erupted in 2014 after the Houthis seized Sanaa. Months later, Saudi Arabia and its allies launched a devastating air campaign to dislodge the Houthis and restore the internationally recognised government.

The conflict has, in recent years, become a regional proxy war that has killed more than 150,000 people, including over 14.500 civilians. It also created one of the worst humanitarian crises in the world.

The Houthis' Friday attack came ahead of a Formula One race in the kingdom on Sunday, raising concerns about Saudi Arabia's ability to defend itself against the Iranian-backed rebels.

Friday's attack targeted the same fuel depot that the Houthis had attacked in recent days, the North Jiddah Bulk Plant that sits just southeast of the city's international airport and is a crucial hub for Muslim pilgrims heading to Makkah.

Satellite photos from Planet Labs PBC analysed by The Associated Press showed one of the two tanks damaged in the Houthi attack on Jeddah still burning late on Saturday morning. Bright red flames leaped up from the tank, with thick black smoke rising from the fire.

The attack appeared to target new tanks, as a tank twice struck by the Houthis just two rows north appeared untouched in the new attack. A tank alongside the burning one appeared to have white wrap and fire-suppressing foam around it.

In Egypt, hundreds of passengers were stranded at Cairo International Airport after their Jeddah-bound flights were cancelled because of the Houthi attack, according to airport officials.

The kingdom's flagship carrier Saudia announced the cancellation of two flights on its website. The two had 456 passengers booked. A third cancelled flight with 146 passengers was operated by the low-cost Saudi airline Flynas.

Some passengers found seats on other Saudi Arabia-bound flights and others were booked into hotels close to the Cairo airport, according to Egyptian officials who spoke on condition of anonymity because there were not authorised to brief media.