Iran 'strongly denies' arming Yemen Houthi rebels

"We have no arms link with Yemen," Tehran's foreign ministry spokesman Bahram Ghasemi told the ISNA news agency.

The statement comes after Saudi Arabia said it had intercepted a rebel missile over Riyadh on Tuesday, suggesting it was "Iranian-manufactured".

"The accusation that Iran gives weapons to various groups is rejected and we strongly deny it," he said.

"Yemen is in a blockade and such possibility does not exist anyway."

The audacious attack aimed at the heart of Saudi power follows the downing of another missile last month near Riyadh airport that triggered the tightening of a Saudi-led blockade on hunger-stricken Yemen.

Weapons used by the rebels "to defend against violation and non-stop attacks" are leftovers of previous governments, Ghasemi said.

"There isn't even the possibility of sending humanitarian aid."

The Saudi-led coalition has been waging war on the Houthis in Yemen since March 2015 while simultaneously accusing Iran of backing the rebels.

"The possession of Iranian-manufactured ballistic weapons by terrorist organisations, including the Iran-backed Houthi militia, is a threat to regional and international security," the Saudi-coalition spokesman said on Tuesday.

US ambassador to the UN, Nikki Haley, described the strike as bearing "all the hallmarks of previous attacks using Iranian-provided weapons".

She said Washington will be discussing options for Security Council action against Tehran, although that immediately drew strong reservations from Moscow.

Over the past three years, more than 10,000 people have been killed and three million displaced since the Saudi-led coalition launched an air campaign against Houthi rebels and their allies in March 2015, triggering what the UN has called the world's worst humanitarian crisis. The war has also led to outbreaks of cholera and brought the country to the brink of famine.

On Tuesday, hundreds of world figures urged the leaders of the United States, France and Britain on to stop “stoking the flames of war” in impoverished Yemen. The statement, signed by 355 high-profile figures, marked the 1,000th day of the war, which has turned the poorest Arab country into the world’s largest humanitarian crisis.

The signatories included eight Nobel peace laureates, religious leaders, Western lawmakers and rights defenders, as well as US Congresswomen Barbara Lee and Pramila Jayapal, and Congressman Ro Khanna, all Democrats.

“To prevent further catastrophe and famine, Yemen needs an immediate ceasefire; an end to all blockages on access for food, fuel and medical supplies; and investment in a new, inclusive peace process,” the statement read.

Agencies contributed to this report