CNN has obtained closed circuit security camera footage from inside the Westgate Mall in Kenya, taken on the day armed gunmen stormed the shopping center. The soundless footage shows panicked shoppers and mall workers fleeing as the attack unfolds, but it has also provided authorities clues to the methods and organization of the group responsible. At least 67 people were killed in attack, the worst terrorist incident in Kenya since the U.S. embassy bombing in 1998.

While the network either does not have or didn't show the most gruesome moments of the attack, the cameras appears to have captured most, if not all of the attackers' movements on that day. The gunmen can be seen firing at citizens and police, gathering hostage, in some of the stores, and communicating with each other. As the attack turned into a protracted hostage situation, the terrorists were even spotted taking breaks and praying during lulls in the assault.

Cameras also captured the men talking on cellphones at several different points, leading investigators to believe that they may have been taking orders from or relaying their activities to someone else outside of the mall. The al-Shabab terrorist group, based in Somalia, has claimed responsibility, but no individuals have been singled out as planners or ringleaders.

You can watch CNN's report on the footage below. While there is no sound and most of the worst moments are off camera, some of the images are disturbing.