Malki, quoted by the official Saudi Press Agency, did not identify the type of "projectile" but said it was "launched deliberately to target civilians" and warned of retaliation. The US, he said, is closely following developments in Hodeidah and urged Emirati leaders to preserve "the free flow of humanitarian aid and life-saving commercial imports". The fighting has escalated as government forces close in on the Red Sea port city of Hodeida - a vital lifeline through which most of Yemen's food and medicine enters.
Last week, Lise Grande, the United Nations humanitarian coordinator for Yemen, warned: "A military attack or siege on Hodeida will impact hundreds of thousands of innocent civilians".
Yemen has been embroiled in a civil war pitting the coalition against the Iran-backed Houthis since March 2015. Some 600,000 people live in and around the city. The Saudi-led coalition faces widespread worldwide criticism for its airstrikes in Yemen that kill civilians.
The Houthis, an Iran-allied group that controls much of Yemen, including the capital Sanaa, have fired a series of missiles into the kingdom in recent months, part of a three-year-old conflict in Yemen widely seen as a proxy battle between Saudi Arabia and Iran.
The conflict in Yemen has left almost 10,000 people dead in what was already the Arab world's poorest country.