Saudi Crown Prince Mohammed bin Salman said on Tuesday that Iran's supply of missiles to Yemeni rebels may be considered an act of war against the kingdom.
In a phone call with British foreign minister Boris Johnson, Prince Mohammed said Tehran's arming of the Houthis was a direct military aggression towards Saudi Arabia, the state-run Saudi Press Agency (Spa) said.
It comes after the kingdom intercepted a Houthis-launched ballistic missile north-east of Riyadh on Saturday evening. Fragments of the missile landed in an uninhabited area.
A Saudi-led coalition is fighting the Houthis in Yemen to restore the internationally-recognised government of president Abdrabu Mansur Hadi. On Monday, the coalition blamed Iran for supplying the rebels with the Burkan H-2 missile launched at Riyadh two days before, after analysing fragments of the missile.
"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,” Spa quoted the alliance as saying.
The coalition also said the kingdom had a "legitimate right" to defend its territory and people and reserved the right to respond to Iran according to “international law and based upon the right of self-defence”, Spa reported.
The Iran-backed Houthis claimed the missile, which has a range of 800-2,000 kilometres, had struck its target — the King Khaled International Airport located 20km north of Riyadh. But the Saudi Civil Aviation Authority said the missile did not cause any damage to the airport and that flights were not disrupted.
The Yemeni rebels have fired dozens of missiles into Saudi territory since the coalition intervened in the war there in March 2015, with Burkan H-2s also being fired at Saudi oil refineries in Yanbu in July and Makkah last month. But the attack on Saturday evening demonstrates that much of the GCC, including the UAE, is within range of the Burkan H-2.
On Monday night, a Houthi-linked military spokesman in the Yemeni capital threatened escalation against the UAE and Saudi Arabia, saying the rebels consider the two countries' airports "legitimate targets".
Colonel Aziz Rashed said in Sanaa that his military experts are able to develop missiles with ranges that exceed 1,500 kilometres.
In his phone call with the Saudi crown prince, Mr Johnson condemned the Houthis' missile launch on Saturday and denounced the deliberate targeting of civilians, Spa reported.