This story has been updated.
The U.S. targeted senior leaders of the shadowy Khorasan Group Wednesday night with airstrikes conducted in the vicinity Sarmada, a town in northwestern Syria near the city of Idlib.
In total, the U.S. conducted five airstrikes with a combination of manned and unmanned aircraft, a defense official told FP Wednesday night.
U.S. Central Command confirmed the strikes Thursday, and said they were carried out by the U.S. alone.
"We are still assessing the outcome of the attack, but have initial indications that it resulted in the intended effects by striking terrorists and destroying or severely damaging several Khorasan Group vehicles and buildings assessed to be meeting and staging areas, [improvised explosive device]-making facilities and training facilities," Centcom said in a statement.
It is believed that French bomb maker David Drugeon is among those killed in the attacks.
The U.S. first struck the Khorasan Group, a small cell of senior al Qaeda operatives, on Sept. 22, the night of the initial airstrikes against Islamic State targets in Syria. To bomb Khorasan Group targets that time, the U.S. relied on Tomahawk missiles launched by the U.S. Navy.
Explaining why the U.S. had gone after a group other than the Islamic State, officials at the time said Khorasan attacks against Europe and possibly the United States were "imminent," and there were fears about the group’s ties to the chief bomb-maker for al Qaeda in the Arabian Peninsula.
About the Nov. 5 attacks, Centcom said,
"This network was plotting to attack in Europe or the homeland, and we took decisive action to protect our interests and remove their capability to act."
After conflicting reports following the September strikes, the intelligence community concluded that the group’s senior leaders — Muhsin al-Fadhli and Drugeon, a possible former French intelligence officer who defected to al-Qaeda — had most likely survived the attack.
Officials and terrorism experts said they thought Khorasan may have been alerted to the impending strike by news reports citing anonymous U.S. officials.
The Syrian Observatory for Human Rights, a monitoring group, reported the Nov. 5 strikes had targeted al-Nusra Front, the local branch of al-Qaeda with whom the Khorasan Group works. Nusra Front has been one of the leading groups fighting the regime of Syrian President Bashar Assad, and therefore draws some support in Syria from those who oppose the government.
Nusra Front had recently made gains against Western-backed factions of the Syrian opposition in the province of Idlib, posing potential new problems to the Obama administration’s strategy of vetting and training Syrian rebels to fight the Islamic State.
Centcom emphasized the most recent strikes were not against the larger Nusra Front organization, but specifically against those involved in plotting attacks against the West.
"These strikes were not in response to the Nusrah Front’s clashes with the Syrian moderate opposition, and they did not target the Nusrah Front as a whole," Centcom said in its statement. "They were directed at the Khorasan Group whose focus is not on overthrowing the Asad regime or helping the Syrian people. These al-Qaeda operatives are taking advantage of the Syrian conflict to advance attacks against Western interests."
But Centcom acknowledged how intertwined the Khorasan Group and Nusra Front are, describing the Khorasan Group as
"a term used to refer to a network of Nusrah Front and al-Qaeda core extremists who share a history of training operatives, facilitating fighters and money, and planning attacks against U.S. and Western targets."