About 25,000 tons of wheat will be offloaded on Monday for starving people in Yemen, the first food aid allowed into the country facing mass famine after a three-week blockade by a Saudi Arabia-led military coalition.

A spokesperson for the World Food Programme (WFP), Abeer Etefa, said the shipment landed on Sunday at the Houthi rebel-controlled Red Sea port of Saleef in western Yemen.

The Saudi-led coalition battling Houthi fighters imposed the siege on Yemeni ports and airports in response to a ballistic missile they fired at the Saudi capital, Riyadh, which was shot down earlier this month.

UN officials have warned that Yemen could face the world's largest famine in decades unless the crippling blockade by the coalition is lifted. The impoverished Middle Eastern country is highly dependent on imported wheat.

Saleef port is 70km north of the key port of Hudeida, also on the Red Sea and in rebel hands. Hudeida Port is the main conduit for UN-supervised deliveries of food and medicine, but the UN says it remains blocked by the Saudi-led coalition.

On Saturday, about 1.9 million doses of vaccines were also flown into Yemen, a UN children's agency official said on Sunday.

But two UNICEF vessels carrying food, water purification tables, and medicine heading to the Hudeida port have not yet received clearance to dock, UNICEF director Geert Cappelaere told reporters in Jordan's capital, Amman.

"We hope all will live up to their promises. These supplies are urgently needed," said Cappelaere.

More than 11 million children in Yemen are in dire need of aid. It is estimated every 10 minutes a child in Yemen dies of a preventable disease, he said.

"Today it is fair to say Yemen is one of the worst places on Earth to be if you're a child. The war in Yemen is sadly a war on children. Yemen is facing the worst humanitarian crisis I have ever seen in my life," Cappelaere said.

The UN has listed Yemen as the world's number one humanitarian crisis with 17 million people in need of food - seven million of whom are at risk of famine.

More than 2,000 Yemenis have died in a cholera outbreak now affecting nearly one million people.

Yemen's civil war has raged since 2015 when the Houthis stormed the capital, Sanaa, and deposed the government of President Abd-Rabbu Mansour Hadi.

Since then the Houthis have been dislodged from most of the country's south, but remain in control of Sanaa and much of the north.

PHOTO CAPTION

Children protest outside UN offices in Sanaa last week [Reuters]

Al-Jazeera