UN Secretary-General Ban Ki-moon on Monday voiced support for the creation of an independent body to probe rights violations in Yemen following air strikes on a funeral ceremony.
Ban said the Geneva-based Human Rights Council must now set up a "full inquiry" in Yemen after the body last month declined to set up such an investigation.
"There must be accountability for the appalling conduct of this entire war," Ban told reporters.
"I urge the Human Rights Council to fulfil its duty and act."
In late September, a group of European states, led by the Netherlands, spearheaded a push at the council for a resolution setting up an international inquiry.
In the end, the EU-backed resolution was scrapped, leaving only a competing and far milder text on the table, drafted by Sudan.
Saudi Arabia, which is leading a military coalition in support of Yemen's government against Iran-backed Huthi rebels, has been staunchly opposed to such a probe.
The UN chief said the air strikes on a funeral ceremony that killed more than 140 people was a "heartless attack on civilians and an outrageous violation of international humanitarian law."
"This was a community centre known to all. It was crowded with families and children," he added.
"Bombing people already mourning the loss of loved ones is reprehensible," he added, noting that initial reports indicated that it was a coalition attack.
The attack, one of the deadliest since the coalition launched a military campaign in March last year, also wounded more than 525 people.
Russia, which has criticized the Saudi-led military campaign in Yemen, separately blocked a Security Council statement condemning the funeral bombing and calling for a return to a ceasefire.
Ambassador Vitaly Churkin dismissed the statement drafted by Britain as "extremely weak and general" and said there was a need to consider new diplomatic steps on Yemen.
"Some very serious thinking needs to be done on the situation in Yemen," he said, without elaborating.
Churkin said the UN envoy for Yemen, Ismail Ould Cheikh Ahmed, who was due to brief the council next week, had asked to postpone his report until October 31.