The missiles were fired by the Iran-aligned Huthi militant group, the coalition said in a statement released Thursday by the official Saudi Press Agency (SPA).

"They were launched in a systematic, deliberate manner to target cities and civilians, which is a flagrant defiance of international humanitarian law," coalition spokesman Turki al-Maliki said, according to SPA.

"The capital (Sanaa) has become a Huthi militia assembly, installation and launching hub for ballistic missiles that target the kingdom," he added.

Saudi Arabia has repeatedly accused Iran of supplying sophisticated weapons to the Huthis, a charge Tehran denies.

The coalition intervened in support of the Yemeni government in 2015 when President Abedrabbo Mansour Hadi fled into Saudi exile as the rebels closed in on his last remaining territory in and around Aden.

Since then, the conflict has killed tens of thousands of people, many of them civilians, relief agencies say.

The fighting has triggered what the United Nations describes as the world's worst humanitarian crisis, with millions displaced and in need of aid.