Saudi air defenses intercepted ballistic missiles over Riyadh and a city along the Yemen border late Saturday, leaving at least two civilians wounded in the curfew-locked capital amid efforts to curb the coronavirus pandemic.

Multiple explosions shook the Saudi capital in the attack, which the Saudi-led military coalition blamed on Yemen's Iran-aligned Houthi rebels, who have previously targeted Saudi cities with missiles, rockets and drones.

It was the first major assault on Saudi Arabia since the Houthis offered last September to halt attacks on the kingdom after devastating twin strikes on Saudi oil installations.

There was no immediate comment from the rebels.

At least three blasts rocked the capital – under a 15-hour coronavirus curfew – just before midnight. The assault comes despite a show of support on Thursday by all of Yemen's warring parties for the United Nations' call for a ceasefire to protect civilians from the coronavirus pandemic.

Saudi Arabia, the Yemeni government and the rebels all welcomed an appeal from UN Secretary-General Antonio Guterres for an "immediate global ceasefire" to help avert disaster for vulnerable people in conflict zones.

The call coincided with the fifth anniversary of Saudi Arabia's military intervention in Yemen's civil war, which was launched to shore up the internationally recognized government against the Houthi rebels.

Yemen's broken healthcare system has not so far recorded any COVID-19 case, but aid groups have warned that when it does hit, the impact will be catastrophic. The country is already regarded as facing the world's worst humanitarian crisis.

Saudi Arabia is also scrambling to limit the spread of the disease at home. The kingdom's health ministry has reported 1,203 coronavirus infections and four deaths from the disease so far.

Fighting has recently escalated again between the Huthis and Riyadh-backed Yemeni troops around the strategic northern districts of Al-Jouf and Marib, ending a months-long lull.

The warring sides had earlier shown an interest in de-escalation, with a Saudi official saying in November that Riyadh had an "open channel" with the rebels with the goal of ending the war.

The Huthis also offered to halt all missile and drone attacks on Saudi Arabia after strikes on its oil installations last September, which were claimed by the rebels but widely blamed on Iran, despite its denials. But those efforts seem to have unravelled. Observers say the rebels may have used the lull to bolster their military capabilities.

Riyadh had expected a quick victory when it led an intervention in 2015 to oust Houthi rebels, under a newly assertive foreign policy led by Crown Prince Mohammed bin Salman. But the costly intervention has failed to uproot the rebels from their northern strongholds, while pushing the Arab world's poorest nation into a humanitarian crisis.

(With input from AFP)