Saudi Arabia has lashed out at Iran over the firing of a ballistic missile towards Riyadh by Houthi rebels in Yemen, citing evidence that Tehran was behind the attack and labelling it a potential "act of war".

A statement issued on Monday via the state news agency SPA denounced the "flagrant military aggression by the Iranian-controlled Houthi militias" and said that an examination of the debris "confirmed the role of Iran's regime in manufacturing [this and a previous missile] and smuggling them to the Houthi militias in Yemen for the purpose of attacking the Kingdom, its people, and vital interests".

The statement accused Iran of violating the United Nations Security Council Resolution 2216, which prohibits states from supplying weapons to Yemeni armed groups.

"Iran's role and its direct command of its Houthi proxy in this matter constitutes a clear act of aggression that targets neighboring countries, and threatens peace and security in the region and globally," the SPA statement noted.

"Therefore, the Coalition's Command considers this a blatant act of military aggression by the Iranian regime, and could rise to be considered as an act of war against the Kingdom of Saudi Arabia."

The statement also noted that Saudi Arabia would temporarily close all Yemeni ground, air and sea ports while investigating how the missiles were smuggled in. Yemen's national airline, Yemenia, subsequently cancelled all flights to the country.

Iran's Revolutionary Guards and political leaders have rejected allegations of the country's involvement in the strike.

Push for confrontation

On Sunday, Saudi Arabia issued a statement offering tens of millions of dollars in rewards for information leading to the arrest of 40 "leaders and elements" of the Houthi group.

The Saudi-led coalition fighting against Yemen's Houthi rebels rained air strikes on Sanaa province on Sunday, just hours after the firing of the ballistic missile.

The civilian death toll of the Saudi-led war in Yemen, launched in March 2015, has surpassed 10,000. Analysts have described the conflict as a proxy war between Saudi and Iran as they battle for regional supremacy.

The surprise resignation of Lebanese Prime Minister Saad Hariri in Riyadh on the weekend also comes in the context of Saudi's renewed push to confront long-time rival Iran.

In his resignation speech, Hariri, a long-time ally of Saudi Arabia, accused Iran of sowing "disorder and destruction" in Lebanon. He also criticised Hezbollah, a Lebanese political and armed resistance movement allied with Tehran, for building "a state within a state".