Washington: Days after shooting in Californian City San Bernardino claimed 14 lives, a top American think tank on Friday claimed the terrorist attack was conducted by perpetrators inspired by the Islamic State and possibly linked to al Qaeda.
Seventeen people were injured in the shooting.
In an op-ed, the Institute for the Study of War (ISW) noted: "Individuals inspired by the Islamic State (ISIS) and with links to al Qaeda conducted the terrorist attack in San Bernardino on December 2.”
This attack was the first al Qaeda- or ISIS-related in the US by a skilled shooter team using both guns and explosives, a technique that both groups used in the Mumbai attacks of November 2008, the Westgate Mall attack in Kenya in September 2013 and the attack on Charlie Hebdo magazine in January 2015 and on several targets in Paris on November 13, it said.
"It marks a step-change in the threat that both al Qaeda and ISIS pose to the security of the American homeland," said the institute in its analysis of the San Bernardino shooting.
The FBI had yesterday said it is investigating the mass shooting as an act of terrorism.
The attack, ISW wrote, displays some of the sophistication and signatures of past al Qaeda attacks.
FBI has named two suspects -- Tashfeen Mailk, a mother of six-month old baby, along with her husband, Chicago-born Syed Rizwan Farook, 28. Both were killed on the same day by the police in an exchange of fire.
Drawing a sharp dividing line between al Qaeda and ISIS threat groups when it comes to attacks on the homeland is difficult despite differences between them in the Middle East.
"The US must expect that both groups will devote even greater resources to encouraging and supporting such attacks here and in Europe now that their feasibility has been demonstrated in both regions," it said.
“American and Western efforts against al Qaeda and ISIS globally are failing and require fundamental reassessment," the think tank said.
ISW said this attack seems likely to be the result of cultivation, inspiration, and possibly planning initially begun by al Qaeda affiliated groups or individuals, and then either co-opted by or simply dedicated to ISIS.
Farook's travels and itinerary suggest that the start of his radicalisation may have predated the re-emergence of ISIS as a major player in June 2014. His connections ran to al Qaeda affiliates al Shabaab and Jabhat al Nusra rather than to ISIS.
Yet Malik pledged to ISIS before or during the attack, and ISIS followers have been cheering the attack and calling them both "lions of the caliphate”.
"It is nevertheless an interesting coincidence that the attack followed by a day the release of a statement by al Qaeda leader Ayman al Zawahiri calling for precisely such attacks against the West," ISW said.
(With PTI inputs)