Stephen O'Brien, the UN under-secretary-general for humanitarian affairs, yesterday said he was "deeply disturbed" by the news that civilians had been killed in Wednesday evening's bombing.
"I call for a swift, transparent and impartial investigation into this incident," O'Brien said in a statement. "Real accountability for parties to conflict, whether they are states or non-state groups, is urgently needed, to ensure that the commitment under international law to protect civilians is meaningful," he added.
O'Brien quoted Yemen's ministry of public health as saying that at least 47 people were killed and 35 were injured, among them many women and children, in the strike.
Medical sources confirmed at least 28 deaths to AFP. The raid hit a house where dozens of people were celebrating in the town of Sanban in Dhamar province, 100 kilometers south of the capital Sanaa, residents said.
It was the second alleged air strike by the Saudi-led coalition on a Yemeni wedding party in just over a week.
But the coalition, under mounting criticism over the civilian death toll of its bombing campaign against Iran- backed Shiite rebels, denied any involvement in the latest attack.
O'Brien noted that 4,500 civilians have been killed or injured since the Saudi-led coalition began air strikes against rebels in Yemen in March.
"That is more than in any country or crisis in the world during the same period," he noted.
The strongly-worded statement underscored that the sides have a responsibility under international law to avoid damage to homes and other civilian structures.
"With modern weapons technology, there is little excuse for error," he added.
A Western-backed resolution calling for a UN investigation into rights abuses committed during the conflict in Yemen was withdrawn last week at the UN rights council due to protests from Saudi Arabia.