Video: Kenya mall attacks: chilling new video emerges The early moments of the footage showed crowds of families and shoppers at the entrance to the mall's Nakumatt supermarket, going about their normal business. Moments later, people begin running in panic. One father grabs his son by the hand and hurries him into the rear of the store. Other people can be seen falling over each other in their hurry to escape the attackers. The video showed how, within just a few minutes, an area that was packed with shoppers is left empty apart from one man cowering behind a cashier counter. However, he is spotted by one of the terrorists who calmly saunters into the supermarket and then shoots him from little over two feet away. Lying in a pool of blood, the victim attempts to gather his strength and crawl away, before slumping back onto the tiled floor. Another gunman then walks in and shows no mercy. The video, gathered by CNN, showed only four gunmen from the beginning of the 80-hour ordeal. Two entered from the ground floor front entrance of the shopping centre, shooting indiscriminately as they moved deeper into the mall towards the busy supermarket. Another pair walked up a vehicle ramp to the top floor car park, where a camera captured them as they headed calmly towards an area where a children's cookery competition was being held. They moved out of the frame before they started shooting. It is thought that most of those who died were killed in the first four hours of the attack. Other footage from the second floor balcony showed people running for their lives as the yellow flash of bullets flew past them. Many scrambled on all fours to try to avoid the gunfire, looking for safety inside shops or behind the counters of cafes. On one occasion, one of the gunmen was seen shepherding four children led by Amber Prior, a French woman, away from the supermarket. Mrs Prior's two children walked unaided, but another needed to be pushed to safety in a supermarket trolley. A fourth child, a teenage girl, was limping and her white hoodie top was in parts soaked in blood. She appeared to be talking to one of the gunmen as he shooed her away towards the supermarket's exit. Other cameras caught the gunmen apparently taking a rest break in a large store-room. While two lounged on office chairs, a third laid out a mat and began to pray. The four gunmen all wore casual long-sleeve shirts, black scarves wrapped around their heads, and tool belts strapped around their waists apparently carrying ammunition and grenades. After the initial assault, they were pictured deeper inside the supermarket talking on their mobile telephones. One appeared to be looking towards the ceiling for CCTV cameras. One of the gunmen, a stockier man in a black jacket, was wounded and left trouser leg was stained with blood. Despite this, he and his accomplices were able to continue shooting as security forces tried to take back control of the shopping centre. The footage is all from the first day of the attack, September 21. Human remains, a live grenade and three assault rifles were yesterday recovered from the rubble at the rear of the supermarket, Kenyan police said. Bomb disposal experts carried out a controlled explosion of the grenade. It was not clear if the human remains, which included a skull, were from an innocent victim of the attack or one of the gunmen. The Kenya Red Cross has 23 names on its list of people missing since the attack almost a month ago. The footage came as a propaganda video emerged for the Somali terror group al-Shabaab - which is suspected of being behind the Nairobi attack - in which apparent members of the group boasted of their links to Britain. One masked jihadist, speaking with a London accent, narrated the names of men with links to the UK, before listing ten British towns where he claimed recruits had come from. He was shown introducing one militant who then referenced the London borough of Tower Hamlets. Watch CNN's new CCTV footage from the Nairobi's Westgate Shopping Centre attack