Thousands have taken to Yemen's streets in protest after at least 140 were killed when an airstrike hit a funeral on Saturday.
Demonstrators gathered around the UN building in capital city Sanaa, calling for an investigation and blaming the organisation for failing to end the conflict.
At least 525 were injured in the airstrike, according to health officials.
The attack was one of the deadliest in the country's civil war and has been blamed on the Saudi-led coalition.
ITV News was at the scene on Sunday and was shown remnants of a bomb, which a Yemeni military official has claimed came from a US-made Mark 82.
The airstrike was denounced as "genocide" by Mohammed Abdul-Salam, the Houthi spokesman in Sanaa.
"The silence of the United Nations and the international community is the munition of the murderers," he said, referring to the Saudi-led coalition.
"Those murderers will not escape divine justice."
In a statement, Saudi Arabia said: "The coalition supporting the legitimate government in Yemen has announced that it is aware of reports about the regrettable and painful bombing of the Great Hall in Sanaa, which led to the killing and injuring of casualties, as reported.
"The coalition confirms that its troops have clear instructions not to target populated area and to avoid civilians."