Yemen's Ansar Allah political opposition movement insists that its ballistic missile attack in the Marib province hit a camp for troops loyal to the ousted Yemeni president, Abdrabbuh Mansur Hadi.
The Houthis denied claims by Hadi's Saudi-backed rival government in the port city of Aden that the missile landed near a petrol station in Marib City, killing 17 people, including civilians and troops.
The Iran-supported Houthis have been steadily gaining ground from the Saudi-backed forces in Marib for months, threatening to again take the provincial capital.
Saudi Arabia, with US logistical support, and a military coalition of regional states joined the Yemen civil war under the invitation of the Yemen's president-in-exile, Abd-Rabbu Mansour Hadi, in 2015, in an attempt to force the reinstatement of Hadi to the presidency following a hotly-contested election in the Middle East's poorest nation.