The Houthi-run al-Masirah TV said earlier that a Badr 1 missile had targeted the city of Jizan, where Saudi Aramco is building a 400,000-barrel-per-day refinery that is expected to become fully operational in 2019.

There were no immediate reports of damage or casualties.

The Iran-aligned Houthis, who control Yemen’s capital Sana’a, have fired dozens of missiles into the kingdom in recent months, part of a three-year-old conflict widely seen as a proxy battle between regional rivals Saudi Arabia and Iran. Most of the missiles have been intercepted by the Saudi military.

A military coalition led by Saudi Arabia and the United Arab Emirates intervened in Yemen’s war in 2015 to unseat the Houthis and restore the internationally-recognized government in exile.

The Western-backed coalition has made no major gains in an offensive launched a month ago to wrest control of Yemen’s port of Al Hudaydah from the Houthis, leaving it without the decisive increase in leverage it had sought against the group in UN-sponsored peace efforts.