DAKAR, Senegal — They had gathered for a wedding in a village in central Mali.
The ceremony took place the day before, but about 100 men and teenagers were still celebrating the next afternoon. They prayed together, then dispersed into different groups under some trees.
An hour later, 22 members of the wedding party were dead, killed by French warplanes. Nineteen of them were civilians, according to a report released Tuesday by the United Nations.
The airstrike, on Jan. 3, set off outrage in the West African country and has intensified calls for France, which has more than 5,000 troops stationed in the region, to leave.
Soon after the airstrike, on the village of Bounti, reports began to emerge that a wedding had been hit. France immediately dismissed any suggestion that its planes had attacked a wedding party or that there had been any collateral damage.
But an investigation carried out by the United Nations peacekeeping mission in Mali found that it was, indeed, a wedding, a report released Tuesday said. French officials again rejected the accusation and called the findings unsubstantiated.
In its report, the U.N. mission found that five gun-carrying members of an armed Islamist group were among the guests at the wedding. They were presumed to be members of the jihadist group Katiba Serma, which is thought to be loosely affiliated with Al Qaeda.
Two of the militants left before the strike, the investigators found, while three were killed. But the rest of the dead were civilians, the report said, suggesting that the French had acted rashly.
“The fact that a certain number of adult men come together in an area where an armed group is active, or the absence of women and children, although useful for context, is far from enough to determine who is a member of an armed group, or that there weren’t any civilians present,” the report said.
The French Army did not deny that the attack had taken place, claiming shortly afterward that it had “neutralized about 30 GAT” — using the French acronym for armed terrorist group.
On Tuesday, following the publication of the U.N. report, the French military launched an attack of another sort: on the report and its methodology, including its use of unnamed sources.
“The only concrete sources on which this report is based come from local testimonies,” the French Defense Ministry said in a statement. It asserted that the report did not “provide any evidence contradicting the facts as described by the French armed forces.”
The French reaction did little too ease the outrage.
Ousmane Diallo, an Amnesty International researcher in Francophone West Africa, described France’s reaction as shocking. “Talking about disinformation, as people mourn their dead,” he wrote on Twitter.
At the very least, critics said, the French Army should try harder to establish what happened.
“It’s more than enough to spur the French government to revisit their original assertion and to open up an investigation,” said Corinne Dufka, the West Africa director of Human Rights Watch.
Asked for his reaction to the French criticism of the report, Stéphane Dujarric, a spokesman for the United Nations secretary-general, António Guterres, told reporters that “we stand by the report and the work of our colleagues in Mali.”
The findings, Mr. Dujarric said, raise “very significant concerns” about what steps countries take to verify that targets are legitimate military objectives.
France’s war on Islamists in the Sahel — a vast arid region south of the Sahara — has dragged on for years with no end in sight. Just last week, French troops were accused of killing more civilians, this time in northern Mali. France said they were terrorists; a local mayor said they were teenagers hunting birds.
The report called for France and Mali to carry out their own investigations into what happened at the wedding and pay compensation to the victims.
Constant Méhuet contributed reporting from Paris.