The UN envoy to Yemen, Ismail Ould Cheikh Ahmed, has said that the death toll in the Yemeni war had reached 10,000, up from the previous figure of 7,000.
The UN envoy's statement came after his talks in Aden with the Yemeni President Abd Rabbuh Hadi who rejected the UN peace plan.
"A peace agreement, including a well-articulated security plan and the formation of an inclusive government, is the only way to end the war that has fuelled the development of terrorism in Yemen and the region," Ould Cheikh Ahmed said in a statement.
Under the proposal, Hadi's powers would be dramatically diminished in favor of a new vice president who would oversee the formation of the interim government that will lead a transition to elections.
Houthi rebels and forces loyal to former president Ali Abdullah Saleh, who control the capital, Sanaa, have faced a military campaign by the Saudi-led coalition to restore President Hadi as the recognized government.
Indiscriminate air strikes have been unable to dislodge the Houthis from the capital and their strongholds in the north of the country. The airstrikes have been criticized for causing widespread civilian casualties and destruction of infrastructure.
An air strike by the Saudi-led coalition on a primary school in militant controlled northern Yemen on January 10, killed five people including two children, according to medical source.
The headmaster and two other staff members were among those killed in the air raid in the district of Nihm, northeast of the capital Sanaa, which also left 13 wounded. A medical source at Kuwait Hospital in Sanaa confirmed the casualty toll.
Human Right groups have repeatedly criticized the coalition over the civilian casualties inflicted by its air strikes on 'rebel'-held regions.
In August last, an air strike on a Quranic school in the northern Saada province killed 10 children and wounded 28 others, prompting a UN call for a swift investigation.
A Saudi strike in October last on a funeral in Sanaa killed some 140 people and wounded over 600.
The higher toll "underscores the need to resolve the situation in Yemen without any further delay", said UN spokesman Farhan Haq in New York. "There is a huge humanitarian cost."
Jamie McGoldrick, humanitarian coordinator of the UN Development Program, said the latest death toll is based on lists of victims gathered by hospitals and the true figure could be higher. McGoldrick said up to 10 million Yemenis were also in urgent need of humanitarian assistance.
"This is one of the world's worst humanitarian crises. People's access to food is rapidly worsening and urgent action is needed," said Salah Hajj Hassan, FAO Representative in Yemen.