UN experts say Iran violated a UN arms embargo by directly or indirectly providing missiles and drones to Shiite rebels in Yemen in a report that also criticizes the rebels and Saudi-led coalition for attacks on civilians.

According to excerpts obtained Friday by The Associated Press and diplomats, the 79-page report paints a devastating picture of the Arab world's poorest nation caught in a conflict that many view as a proxy war between regional rivals Saudi Arabia and Iran.

"After nearly three years of conflict, Yemen as a state has all but ceased to exist," the report said.

The war has caused profound misery among Yemen's 28 million people.

More than 10,000 civilians have been killed in fighting and airstrikes; more than 7 million are on the brink of famine and over 19 million don't know where their next meal is coming from; medical infrastructure has collapsed; and a cholera outbreak has affected 1 million people.

The report said the panel saw "no evidence" that either side took measures "to mitigate the devastating impact" of attacks on civilians.

The rebels, known as Houthis, and forces allied to former president Ali Abdullah Saleh swept into the capital, Sanaa, in 2014. The Saudi-led coalition, backed by the United States, launched an air campaign against the rebels in March 2015 and later expanded into ground operations.

The fighting has been deadlocked for more than a year. Despite a punishing air campaign, the coalition backing Yemen's President Abed Rabbo Mansour Hadi has been unable to gain further ground against the Houthis, who control the capital Sanaa and the north and western part of the country, where most of the population lives.

UN experts travelled to Saudi Arabia in November and December and examined remnants of missiles fired by the Houthis in those months as well as in May and July.

The report said: "The panel has identified missile remnants related to military equipment and military unmanned aerial vehicles that are of Iranian origin and were introduced into Yemen after the imposition of the targeted arms embargo" in 2015.

Referring to the Security Council resolution that imposed the embargo, it said: "As a result, the panel finds that the Islamic Republic of Iran is in non-compliance with paragraph 14 of resolution 2216 in that it failed to take the necessary measures to prevent the direct or indirect supply, sale or transfer of missile and unmanned aerial vehicles to the Houthi-Saleh alliance."

Iran backs the Houthis but denies supplying the rebels with arms.

During a Security Council meeting on Dec. 19, U.S. Ambassador Nikki Haley called the Houthis' firing of a ballistic missile earlier that day aimed at a meeting of Saudi leaders in the capital Riyadh but intercepted by the Saudis "a flashing red siren" and said the U.S. would push for action against Iran but Russia signalled its opposition.

The panel report was also critical of the coalition's air and sea blockade of Yemen imposed after a missile attack by the Houthis near Riyadh on Nov. 6, saying it was using the "threat of starvation as a bargaining tool and an instrument of war."

UN spokesman Stephane Dujarric said Friday that since the coalition's announcement on Dec. 20 that it would open the ports of Hodeida and Salif for a month, "13 vessels have delivered food and much-needed fuel."