A bomb-laden drone launched by Yemen's Huthi rebels crashed into a Saudi school on Sunday, state media said, despite growing diplomatic efforts for a cease-fire between the warring parties.

No injuries were reported in the strike in southern Asir province, the official Saudi Press Agency (SPA) reported, citing civil defense authorities.

Photos released by SPA showed the damaged roof of a building as well as what appeared to be broken parts of the drone.

The reported attack came three days after the Saudi-led coalition fighting the rebels said it had stopped carrying out attacks in Yemen in order to pave the way for a peaceful settlement.

The de-escalation is aimed at "preparing the political ground for a peace process in Yemen," coalition spokesperson Turki al-Maliki told Saudi state television on Thursday.

But shortly after his comments, Yemeni state media reported that at least eight ­civilians had been killed and 27 ­others wounded in strikes in the northern city of Marib.

The United Nations says ­Yemen is suffering the world's worst humanitarian crisis as the country's years-long war rumbles on, with tens of ­thousands killed, millions displaced and two-thirds of its 30 million population dependent on aid.