A tweet posted by an alleged al Qaeda member has added to days of mounting speculation about the possible death of Mohsin al-Fadhli, chief of the al Qaeda-affiliated Khorasan group, following a US-led airstrike in Syria last week.
On Sunday, SITE Intel Group, a jihadist monitoring service, reported that an unnamed militant, who had previously fought with Khorasan elsewhere in the Middle East before arriving in Syria, expressed condolences for the death of 33-year-old Fadhli on Twitter over the weekend. Concrete news of Fadhli's death remains elusive.
A US official told Reuters that Fadhli had been killed in airstrikes conducted September 23 in Syria, but the Pentagon said later the same day that it was was still investigating.
"We want to make sure that he's not trying to, in effect, fake his death and go underground," Tony Blinken, deputy White House national security adviser, said during an appearance on Fox News Sunday. "But there are serious indicators he was removed."
In the leadup to the US-led airstrike campaign in Syria last week, authorities began releasing details of the largely unheard-of Khorasan group, which is allegedly comprised of well-trained jihadists with a long history of operations in Pakistan and Afghanistan.
The shadowy terror cell is now said to have joined forces with al Nusra Front, an al Qaeda-linked group in Syria. Several Nusra Front fighters were also killed in last week's air offensive.
On Tuesday, the Pentagon announced it had successfully deflected plans by Khorasan to stage an "imminent attack" on Western soil through its coordinated airstrikes.
The raids were conducted using "a mix of fighter, bomber and Tomahawk land-attack missiles," against both the Islamic State group and Khorasan in Syria, Lt. Gen. William Mayville, who headed the Syrian airstrike operation, told reporters at a Pentagon press conference.
"We're still assessing the effects of our strikes. But we've been watching this group closely for sometime," Mayville said. "We believe the Khorasan group is — was nearing the execution phase of an attack either in Europe or the homeland. We know that the Khorasan group has attempted to recruit Westerners to serve as operatives or to infiltrate back into their homelands."
Mayville indicated the strikes were just the beginning of their offensive against both terror groups.
"You haven't heard of the Khorosan Group because there isn't one," former federal terrorism prosecutor Andrew McCarthy wrote in a column for the National Review Saturday. "It is a name the administration came up with."
"The 'Khorosan Group' is al-Qaeda," McCarthy wrote. "It is simply a faction within the global terror network's Syrian franchise, 'Jabhat al-Nusra.' Its leader, Mushin al-Fadhli (believed to have been killed in this week's U.S.-led air strikes), was an intimate of Ayman al-Zawahiri, the emir of al-Qaeda who dispatched him to the jihad in Syria."
The State Department previously put out a $7 million reward for information on the whereabouts of Fadhli in 2012, saying the leader was closely tied to Osama bin Laden and was one of a few who knew about the 9/11 terror attacks in advance.
Follow Liz Fields on Twitter: @lianzifields