New details emerging from the military’s investigation into the ambush and interviews with military officials and lawmakers have revealed, once again, changes to the timeline in a shifting narrative that has bedeviled top Pentagon officials. It has prompted increasingly frustrated members of Congress to demand answers for how a shadowy mission in an austere region of Africa left four Americans and five Nigeriens dead, including the interpreter.
The questions — including the mission’s shifting goals, the intelligence assessment to back it up, how the soldiers were separated and the frantic search for Sergeant Johnson’s body — were at the forefront on Thursday when senior military officers and their civilian Pentagon bosses traveled to Capitol Hill to give separate two-hour classified briefings for members of the House and Senate Armed Services Committees.
Senator John McCain, Republican of Arizona, who heads the Senate panel and who has criticized the Defense Department for failing to provide lawmakers details of the ambush, praised the briefing without divulging details. But he emphasized that he still had “100 questions” that the officials could not yet answer.
Pentagon officials said they would need 30 days to wrap up their inquiry, Mr. McCain said. Other senators on the committee said it could take up to 60 days. Army Maj. Gen. Roger L. Cloutier Jr., the chief of staff of the military’s Africa Command in Germany, is leading the inquiry.
“It’s clearer, but there’s still a lot of things that they don’t know,” said Senator Bill Nelson, Democrat of Florida. “Why did it take 48 hours to find Sergeant Johnson? We don’t know that yet.”
Senator Tim Kaine, Democrat of Virginia, said many lawmakers were surprised to learn the scope of American military missions in Africa and, in particular, the size of the military presence in Niger, where 800 United States troops conduct training missions and drone operations. “I don’t think Congress has been completely kept up- to date,” Mr. Kaine said.
The mystery of what happened that day only deepened as new details emerged from interviews with more than a half dozen military officers, Pentagon officials and lawmakers this week.
On the night of Oct. 3, two groups set off in rural southwest Niger. One was a team of American, French and Nigerien commandos on a clandestine operation to kill or capture an Islamic State operative, part of a broader mission code-named Obsidian Nomad. The other group — made up of about eight Army Special Forces, three American soldiers in support roles and their interpreter, along with 30 Nigerien troops — was on a separate reconnaissance patrol. At some later point, the team was asked to back up the first group if needed.
Bad weather scotched the raid, intended to be launched from helicopters. But the second group remained in the region, after being asked by commanders to search further for evidence of the Islamic State jihadist, code-named Naylor Road by the military.
On the morning of Oct. 4, the team swung through the village of Tongo Tongo to resupply and met with local elders out of courtesy. Villagers might have tipped off Islamic State militants in the area, Nigerien and American military officials have said. One military official, however, said on Thursday that a villager told the troops that an important Islamic State emir was in the area, possibly alerting them that the extremists were approaching.
Shortly after the American soldiers, who were led by an Army captain, and the Nigerien troops left the village, heading back to base about two hours away, some 50 Islamic State militants armed with machine guns and heavy weapons ambushed the group at about 11:40 a.m. local time.
Lightly armed with no heavy weapons of their own, the American and Nigerien forces tried to defend themselves. Outgunned and taking casualties, the soldiers tried to stand their ground until additional Nigerien troops rushed to the scene.
It was not clear when the Nigeriens, along with French troops, arrived, but American officials indicated that they had made it to the ambush site by the time the seven Americans were evacuated.
When troops from the elite Joint Special Operations Command were alerted to the situation, however, they were told that several Americans were missing. That calls into question Pentagon officials’ earlier assertions that either the Nigerien forces or French helicopters were with the bodies of at least three of the soldiers until they were recovered — an insistence that underscores the mantra that no soldier is left behind.
“The U.S. military does not leave our troops behind,” Defense Secretary Jim Mattis said last week.
Eventually, the team of American commandos originally scheduled to target the Islamic State militant the previous night were dropped near the ambush site and found the bodies of three of their comrades: Staff Sgt. Bryan C. Black, Staff Sgt. Jeremiah W. Johnson and Staff Sgt. Dustin M. Wright.
But at least one American was still missing. Commandos from Sigonella, Italy, and Djibouti rushed to Niger’s capital, Niamey, while a reserve unit of Special Forces stationed at Africa Command headquarters in Germany prepared to deploy if needed. Sergeant Johnson’s body was found by Nigeriens on the evening of Oct. 6.
After the ambush, American units in the region were forced to change radio frequencies because communications equipment was missing and believed compromised by enemy forces.
The American-backed operations to topple the Islamic State from its strongholds in Mosul, Iraq, and Raqqa, Syria, could increase the risks in Africa, if Islamic State fighters flee to the continent to continue their mayhem there, as some have begun to do.
“The more we succeed in the Middle East, the more we’re going to see the snakes run to Africa,” Senator Thom Tillis, Republican of North Carolina, said on Thursday. “We’ve got to be prepared to advise and assist the nations there that are willing to work with us.”
Some lawmakers, including Senator Richard Blumenthal, Democrat of Connecticut, called for hearings to help explain what went wrong in Niger.
“I need to be able to look families in the eye and explain what our mission is, what mistakes were made in this incident, who made them and why,” Mr. Blumenthal said.