In a statement, the military’s Africa Command said the strike had targeted militants with Al Qaeda in the Islamic Maghreb, an affiliate also known as AQIM, and had been carried out in coordination with the United Nations-backed unity government in Tripoli. “At this time, we assess no civilians were killed in this strike,” the statement said.
The strike came as the Trump administration has been reassessing the American military commitment in North and West Africa after the ambush in Niger last fall that killed four American soldiers. The Pentagon has been preparing to fly armed drone missions from Niger’s capital, Niamey, a step that diplomats and analysts say could further widen the Pentagon’s shadow war in this part of the continent.
In a sign of how the Pentagon has sought to obscure its operations in Libya and other parts of northwestern Africa, the Africa Command did not announce the strike on Saturday.
It responded to questions from The New York Times late Saturday with a terse statement after media reports about the strike circulated in Libya. The statement did not identify where the drone had originated.
Earlier this month, in response to a Times query, the Pentagon acknowledged for the first time that Green Berets working with government forces in Niger had killed 11 Islamic State fighters in a firefight in December. No Americans were hurt in that fight, the Pentagon said.
Ubari is at the intersection of the powerful criminal and jihadist currents that have washed across Libya in recent years. Roughly equidistant from Libya’s borders with Niger, Chad and Algeria, the area’s seminomadic tribesmen are heavily involved in the smuggling of weapons, drugs and illegal migrants through the lawless deserts of southern Libya.
Some have allied with Islamist militias, including Al Qaeda in the Islamic Maghreb, which operates across Algeria, Mali, Niger and Libya.
The area erupted into conflict in 2014 when a century-old peace treaty between the Tuareg and Tebu ethnic groups collapsed over a dispute about control of the fuel smuggling trade. The fighting, which occurred independently of the broader struggle for control of Libya after the 2011 overthrow of Col. Muammar el-Qaddafi, raged for a year, killing hundreds and leaving many families displaced.
The Tebu and Tuareg eventually struck a peace agreement, and a neutral militia currently keeps the peace in Ubari, but tensions remain. In November, Turkish engineers working at the city power station were kidnapped by unidentified gunmen, as was a Pakistani engineer at the station who went missing this month, according to local news media reports.
While some Tebu groups have allied with the United Nations-backed government in Tripoli, Tuareg factions have allied with Qaeda, which is also believed to have profited from the trade in smuggled fuel.
In the statement on Saturday, Robyn M. Mack, a spokeswoman for the United States Africa Command, said that it was still assessing the results of the strike and that the purpose had been “to deny terrorists freedom of action and degrade their ability to reconsolidate.”
But the command did not answer several other questions: Who were the two dead militants, and why were they important enough to kill with an airstrike? What role, if any, did France play in a region of Libya in which it has also conducted counterterrorism operations? And, most significantly, to what extent is the attack the start of an escalating campaign against a broad spectrum of extremists in northwestern Africa, or a one-off strike against high-profile Qaeda operatives?
“Beginning a concerted strike campaign against AQIM or other AQ elements in the Sahel, akin to what we are doing in Yemen and Somalia, would mark a significant expansion of our counterterrorism efforts,” said Luke Hartig, a former senior director for counterterrorism at the National Security Council during the Obama administration.
“If this is going to be the start of a broader campaign, it would be helpful to hear more from the administration about the threat posed by AQIM and why it merits putting our people in harm’s way and conducting strikes,” Mr. Hartig said.
Questions about whether the American military, under the Trump administration, is seeking to blur the expanding scope of operations in Africa were raised this month when it was revealed that the United States had carried out four airstrikes in Libya between September and January that Africa Command did not disclose at the time. The military has said it will acknowledge such missions if asked about them, even if it does not affirmatively disclose them in a news release.
Ms. Mack said that Saturday’s attack was the first airstrike the United States had conducted against Al Qaeda in Libya. In fact, the United States conducted an airstrike in eastern Libya in June 2015 against Mokhtar Belmokhtar, the mastermind of the 2013 terrorist seizure of an Algerian gas plant that left 38 foreign hostages dead. Mr. Belmokhtar was a longtime Qaeda operative with ties to senior Qaeda leadership in Pakistan. Western intelligence officials today remain divided over whether he is dead.
American efforts to hunt down Islamists in Libya’s vast deserts rely heavily on surveillance and airpower but also on alliances with the armed groups vying for control of Libya. Mohamed El Sallak, a spokesman for the United Nations-backed unity government, said on Twitter that the attack in Ubari on Saturday was part of the “strategic cooperation between Libya and the United States in the fight against terrorism.”
But in Ubari, armed Tebu and Tuareg groups have sided with different sides in Libya’s chaotic struggle, and the unity government is by no means the dominant player.
Some control a stretch of southern border, while others have allied with militias from the coastal cities of Misurata and Benghazi. The rising force now in the south is Field Marshal Khalifa Hifter, the commander of the Libyan National Army based in Benghazi.
Since his forces ousted the last Islamist militias from Benghazi in December, Mr. Hifter has focused on the south, where he exerts influence through his fleet of aging warplanes and alliances with local armed groups.
In Sebha, the largest southern city, Mr. Hifter and the rival United Nations-backed government are vying for control through local proxies. In Ubari, 110 miles to the west, Mr. Hifter has allied with an ethnically mixed militia that is composed of former Qaddafi loyalists and more recent recruits.