Yemen’s Al Houthis, with the full backing of Iran, are crossing some dangerous red lines. Saudi air defences intercepted seven missiles on Sunday launched by the militia, including over the capital Riyadh. One Egyptian was killed and two of his fellow countrymen were wounded by falling shrapnel in Riyadh.

“This aggressive and hostile action by the Iran-backed Al Houthis proves the Iranian regime continues to support the armed group with military capabilities,” coalition spokesman Turki Al Malki said.

The fact is these ballistic missiles were fired in the direction of civilian-inhabited areas. While three were launched at Riyadh, four others targeted the southern border cities of Khamis Mushait, Jizan and Najran. The intention was to cause the maximum number of casualties. GCC leaders have condemned the attacks on Saudi Arabia, and Gulf officials have expressed their dismay and outrage while social media users engaged in hard criticism of the unfolding events. Bahraini Foreign Minister Shaikh Khalid Bin Ahmad Al Khalifa said the missiles fired by Al Houthis were from Iran.

“The Al Houthi missiles are Iranian. Self-incrimination. Iran will know the fate awaiting it,” he tweeted.

The sophistication of the weaponry being deployed by the militia clearly points at the involvement of the regime in Tehran. There is no other way a non-state actor like Al Houthis could have got their hands on such missiles.

At a time when measures are being discussed to end the conflict, the action by Al Houthis clearly shows they — and their masters in Tehran — are clearly not interested in a political settlement.

Al Houthis have to realise the coalition will not allow them to spread Iran’s agenda in the region. Saudi Foreign Minister Adel Al Jubeir was right when he said the war in Yemen was imposed on Saudi Arabia, and was not a war of choice. The sovereignty of Yemen and the legitimacy of its recognised government are not negotiable.

Repeatedly, it has been proved that Iran is supplying the militias with weapons ranging from small arms and IEDs to ballistic missiles. Just today, the Conflict Armament Research group said roadside bombs disguised as rocks in Yemen bear similarities to others used by Hezbollah in southern Lebanon and by insurgents in Iraq and Bahrain. What is the common thread that links militias and insurgents in these countries? It’s simple: They are all backed and funded by Iran. And Tehran must be held accountable for its actions.