The Saudi-led coalition fighting in Yemen said it intercepted and destroyed a ballistic missile fired by the Iran-aligned Houthi movement towards the south of the kingdom on Tuesday after intercepting several drones the previous night.

Violence has surged between the Western-backed alliance and the Houthi group after a six-week ceasefire prompted by the coronavirus pandemic expired last month.

A coalition statement said the missile was launched towards the southern region of Najran. It earlier said that it had destroyed several armed drones fired towards the southern city of Khamis Mushait late on Monday.

A Houthi military spokesman said in a Twitter post that the Khamis Mushait attack was in response to coalition air strikes. There was no immediate confirmation of the missile attack.

On Monday, the Houthi health minister said in a Twitter post that a coalition air strike killed 13 people, including four children, in Saada province. The spokesman for the military alliance, Colonel Turki al-Malki, said the accusation was being investigated but that the coalition had not heard the allegation from any other "trusted party".

In the Houthi-held capital Sanaa on Tuesday, several residents said coalition warplanes struck military sites south and west of the city.

The coalition later said it had carried out heavy air strikes on Houthi targets in Sanaa and neighbouring Omran provinces, Saudi state-run Ekhbariya news reported from a coalition statement, without giving further details.

The Houthis ousted Yemen's Saudi-backed government from Sanaa in late 2014, prompting the coalition to intervene.

The uptick in violence comes as Yemen combats the spread of the coronavirus among an acutely malnourished population.

The United Nations says the virus is spreading unmitigated in the country that has shattered health systems and inadequate testing capabilities and that infections are likely much higher than official reports.

The Saudi-backed government based in the south has announced 834 cases, including 208 deaths. The Houthis, who control most big urban centres, have not provided figures since May 16 when authorities said there were four cases, with one death.