ISIS seen building capacity for mass casualty attacks

Updated 8:16 AM EDT, Sat August 8, 2015
isis mass attacks warning sciutto dnt lead_00001006.jpg
PHOTO: ISIS
isis mass attacks warning sciutto dnt lead_00001006.jpg
Now playing
02:00
Is ISIS plotting mass casualty attacks?
Now playing
01:01
Fleeing ISIS in Mosul: Their faces say it all
women flee isis to debaga
PHOTO: CNN
women flee isis to debaga
Now playing
01:58
Women recount horror of life under ISIS
PHOTO: CNN
Now playing
01:30
ISIS survivor tells her story
Nick Paton Walsh Mosul ISIS gunfire orig_00004713.jpg
Nick Paton Walsh Mosul ISIS gunfire orig_00004713.jpg
Now playing
01:20
Iraq forces and ISIS exchange gunfire
Iraqi women react as people gather on July 9, 2016 at the site of a suicide-bombing attack which took place on July 3 in Baghdad's Karrada neighbourhood.

The Baghdad bombing claimed by the Islamic State group killed 292 people, according to a new toll issued on July 7, many of whom were trapped in blazing buildings and burned alive. A suicide bomber detonated an explosives-laden minibus early on July 3, ahead of the Eid al-Fitr holiday marking the end of the holy Muslim fasting month of Ramadan. / AFP / AHMAD AL-RUBAYE        (Photo credit should read AHMAD AL-RUBAYE/AFP/Getty Images)
PHOTO: AHMAD AL-RUBAYE/AFP/Getty Images
Iraqi women react as people gather on July 9, 2016 at the site of a suicide-bombing attack which took place on July 3 in Baghdad's Karrada neighbourhood. The Baghdad bombing claimed by the Islamic State group killed 292 people, according to a new toll issued on July 7, many of whom were trapped in blazing buildings and burned alive. A suicide bomber detonated an explosives-laden minibus early on July 3, ahead of the Eid al-Fitr holiday marking the end of the holy Muslim fasting month of Ramadan. / AFP / AHMAD AL-RUBAYE (Photo credit should read AHMAD AL-RUBAYE/AFP/Getty Images)
Now playing
01:24
Majority of ISIS victims are Muslim
PHOTO: ISIS
Now playing
01:23
Is it ISIS, ISIL or Daesh?
Now playing
02:19
ISIS' battle tactics
PHOTO: CNN
Now playing
00:46
Why Libya matters to ISIS
ISIS hates yazidis terrorist group target orig cm_00000923.jpg
ISIS hates yazidis terrorist group target orig cm_00000923.jpg
Now playing
01:57
ISIS hates this religious group the most
iraq isis human shields damon pkg_00013513.jpg
iraq isis human shields damon pkg_00013513.jpg
Now playing
02:44
Iraqis recount horrors of being human shields for ISIS
isis fratricide robertson pkg_00002526.jpg
PHOTO: SITE Monitoring
isis fratricide robertson pkg_00002526.jpg
Now playing
02:43
ISIS calls on Saudi supporters to kill relatives
ISIS released still pictures purporting to show massive parade of their militants in the city of Sirte, Libya
PHOTO: ISIS
ISIS released still pictures purporting to show massive parade of their militants in the city of Sirte, Libya
Now playing
02:30
Why is ISIS heading to Libya?
iraqi town suffering after isis chemical attack damon pkg cnn today_00010115.jpg
iraqi town suffering after isis chemical attack damon pkg cnn today_00010115.jpg
Now playing
02:34
Iraqi town suffering from ISIS chemical attack
(CNN) —  

Some in the U.S. intelligence community warn that ISIS may be working to build the capability to carry out mass casualty attacks, a significant departure from the terror group’s current focus on encouraging lone wolf attacks, a senior U.S. intelligence official told CNN on Friday.

To date, the intelligence view has been that ISIS is focused on less ambitious attacks, involving one or a small group of attackers armed with simple weapons. In contrast, al Qaeda in the Arabian Peninsula, or AQAP, has been viewed as both more focused on – and more capable of – mass casualty attacks, such as plots on commercial aviation. Now the intelligence community is divided.

Meanwhile, the U.S. effort to train rebels in Syria to fight ISIS is having trouble. The few rebels that the U.S. has put through training are already in disarray, with defense officials telling CNN that up to half are missing, having deserted soon after training or having been captured after last week’s attack by the al-Qaeda-affiliated Nusra Front attack on a rebel site.

Al Nusra claims attack on U.S.-trained rebels in Syria

One defense official admitted to CNN that “they are no longer a coherent military unit,” and Pentagon officials acknowledged the approach of how to support the rebels has to change.

The potential change within ISIS itself is driven – in part – by a broadening competition between ISIS and AQAP for attention and recruits.

That same competition was evident this week when AQAP bomb-maker Ibrahim al-Asiri made an online appeal to supporters to carry out lone wolf attacks.

“I think they’re taking a lot of the new recruits that don’t have time to train, who have not been brought up in their systems, and they’re using them to create the type of mass casualty which produces the media attention, which is exactly what they want, that shows they’re still powerful,” said CNN Military analysts Lt. Gen. Mark Hertling. Meanwhile, ISIS is continuing to draw large numbers of new foreign recruits. U.S. intelligence assesses that the formidable flow of foreign fighters to Syria and Iraq has not abated.