A Yemeni government air strike has killed scores of displaced civilians, mostly women and children, in the war-torn Amran province, witnesses say.

Up to 120 people, including 80 dead were transferred to the local hospital, an ambulance driver who had counted the dead and the injured said on condition of anonymity, fearing government payback.

Three other witnesses reported a similar number of casualties in the area, which is close to the Houthi-controlled city of Harf Sufyan.

Local aid workers and tribal sources said the air strike came around midday. They reported seeing body parts flying in the air and pools of blood where hundreds of the displaced had taken refuge.

Mohammed, a local aid worker working with the displaced, said when the missiles hit the area, people ran for cover under a nearby bridge, which was then targeted by the government warplanes.

"The area turned into a pool of blood. I saw body parts and charred bodies," said Ali, another local aid worker.

A third witness, Yehia, also said that ambulances reached the bombarded area hours after the bombing.

Military officials denied the reported casualties among civilians, claiming that there was no gathering of displaced people in al-Adi. A civil servant in the local government, however, confirmed the attack.

A statement from the Houthi fighters -- also known as the Zaidis -- confirmed that a government air strike had targeted a group of displaced, leaving dozens dead.

The attack was the second government air strike against civilians in three days in the conflict-ridden area of northern Yemen. A new round of fighting broke out in Sa'dah and Amran provinces last month.

The air raid followed a Monday statement by the fighters that Yemeni jets had dropped two bombs on a crowded market in Sa'dah city, killing more than a dozen civilians.

Houthi fighters say the government denies Zaidi Shias, who make up almost half of the Yemeni population, their rights and marginalizes them as Sana'a is allied with Saudi-backed Sunni extremists, who consider Shias heretics.

According to the Red Cross, the new round of attacks that Sana'a has launched against the northern provinces since August 1 has displaced some 30,000 civilians, brining the total count to over 150,000 since 2004.

Most of the displaced civilians have taken refuge in major cities, but some are stranded in remote areas.

On Wednesday, the United Nations announced that an appeal for donations to help the 150,000 Yemeni refugees had received no responses so far.

The director of the UN Office for the Coordination of Humanitarian Affairs said he was alarmed at the lack of reaction to calls by the international body urging efforts to raise the $23 million in aid needed to assist the Yemeni displaced.

"The international community has very little understanding of this crisis… The situation is very bad for the people affected by conflict,” OCHA Director Rashid Khalikov told CNN in New York after a four-day visit to Yemen.

“Visiting the camps, we could see that people have fled with nothing," he added, pointing out that without aid, the problem would worsen.

Thursday reports indicate that the group's leader Abdel Malik al-Houthi has sent a letter to the Secretary-General of the United Nations Ban Ki-moon, informing him about the dire humanitarian conditions civilians face in the Amran and Sa'dah provinces.

Houthi urged Ban to send independent UN committees to monitor a ceasefire with the government and continue relief work.

He also said that he was ready to provide all facilities for the international aid agencies, non-governmental organizations and journalists arriving in areas affected by the conflict.

MJ/AKM