According to witness accounts cited by United Nations human rights investigators, two airstrikes struck the Al Kubra community hall in Sana, seven to eight minutes apart. It was packed with families attending the funeral of a leader of the Houthi rebel movement, which is battling the Saudi-backed government of President Abdu Rabbu Mansour Hadi for control of the country. Many prominent military and political leaders associated with the Houthis were in the hall and were killed in the assault, the United Nations said.

“Aerial attacks by the Saudi-led coalition have already caused immense carnage and destroyed much of the country’s medical facilities and other vital civilian infrastructure,” Mr. Ban said. “Excuses ring hollow given the pattern of violence throughout the conflict. Parties cannot hide behind the fog of this war. A man-made catastrophe is unfolding before our eyes.”

Earlier on Monday, the United Nation’s top human rights official, Zeid Ra’ad al-Hussein, called for an independent international inquiry, noting a sharp rise in civilian casualties since the collapse of Yemeni peace talks in August.

At least 369 civilians have been killed or injured since the start of October, Mr. Hussein said in a statement, bringing total documented civilian deaths since the coalition entered Yemen’s civil war in March 2015 to at least 4,125 and the number of injured to 7,207.

In response to the attack on the funeral, the Islamic Revolutionary Guards Corps of Iran, widely seen as the main backers of the Houthis, issued an angry statement saying that the rebel group, which Iran refers to as the Ansarullah movement, would “avenge” the bombing, and that the attack was “a U.S., Saudi, Israeli joint conspiracy.”