Yemen's Houthi forces said they attacked important targets in the Saudi Arabian capital of Riyadh with four drones on Thursday.

There was no confirmation from Saudi authorities or independent reports of any such strikes.

The Saudi-led coalition fighting the Houthis said it had destroyed a missile before it took off from Yemen, according to a report on Saudi state TV. The report said the Houthis had meant to use it to attack the gas-rich Yemeni province of Ma'rib.

The Iran-aligned Houthis have rejected a ceasefire proposal from Riyadh that did not include the lifting of an air and sea blockade imposed by a Saudi-led military coalition on areas under their control, mainly in northern Yemen.

The conflict, seen in the region as a proxy war between Saudi Arabia and Iran, has caused what the United Nations says is the world's largest humanitarian crisis.

The Saudi-led coalition intervened in 2015 to support Yemen's internationally recognized government after it was ousted from the capital Sana'a by the Houthis.