Hundreds of Yemeni people have held a protest against Saudi Arabia's prolonged war on the impoverished Arab country, blaming the United Nations for its failure to bring the deadly campaign to a decisive end.

The protesters gathered in front of the UN office in the Yemeni capital, Sana'a, on Sunday to express outrage over the misery the Saudi war machine has brought to the country.

The demonstrators said the world body had failed to curb the massive starvation in Yemen and block further displacement of the Yemeni people.

"We are here to tell the United Nations that it is now accused of (contributing to) the starvation of the people of Yemen. It is now responsible for the displacement of the Yemeni people," said Khalil el-Shamri, the head of the workers' syndicate of Yemen, one of the organizers of the demonstration.

In June last year, the UN removed Saudi Arabia and its allies from its list of child rights violators, less than a week after blacklisting them for killing nearly 800 Yemeni children in 2015. The removal prompted angry reactions from human rights groups, which accused then UN Secretary General Ban Ki-moon of caving in to pressure from powerful countries.

Following the controversial U-turn by the UN, Ban admitted that the Saudis were temporarily removed from the list after they administered "undue pressure" on the world body by threatening to cut off funding to its humanitarian programs.

A Yemeni boy sits amid the rubble of damaged houses following Saudi airstrikes on the outskirts of the Yemeni capital, Sana'a, February 1, 2017. (Photo by AFP)

"We came here today to demand the cessation of the war, the opening of the ports and the lifting of the siege of the Yemeni people, who are starving to death. The people are dying due to the siege on their daily needs. Medication is not available," said Amal Nagy, a physician who participated in the rally.

Earlier in the week, UN Under-Secretary General for Humanitarian Affairs Stephen O'Brien reported that seven million people in Yemen did not know where their next meal was coming from. Of that figure, almost 3.3 million, including 2.1 million children, are suffering from acute malnutrition, he said.

Nineteen million out of Yemen's 26-million-strong population are in a pressing need of humanitarian assistance, O'Brien added.

Saudi Arabia has been engaged in the deadly campaign against Yemen since March 2015 in an attempt to reinstall the resigned president, Abd Rabbuh Mansur Hadi, who is a close ally of the regime in Riyadh, and to undermine the Houthi Ansarullah movement.

On February 23, Yemen’s Legal Center for Rights and Development, an independent monitoring group, put the civilian death toll in the war-torn Arab country at 12,041. The fatalities, it said, comprise 2,568 children and 1,870 women.

The relentless Saudi airstrikes have also taken a heavy toll on Yemen's facilities and infrastructure, destroying many hospitals, schools, and factories.