Nairobi mall shooting: BBC film uses CCTV to tell Kenyan story

2013 file photo of armed police taking cover behind escalators as smoke fills the air inside the Westgate Mall during the terrorist attack. Photo / AP

A Briton whose wife was murdered in Nairobi's Westgate shopping centre massacre has told for the first time of their ordeal as Islamist militants unleashed the mayhem that ended with 71 people dead, and of the moment he realised that his wife's life was ebbing away.

Niall Saville, now 36, had been sitting with his South Korean wife, Moon Hee Kang, 38, in a hamburger restaurant facing the street when the attack began with a grenade explosion at 12.30pm, followed by heavy gunfire, one year ago today.

Saville, a development economist, dived into the restaurant, then realised his wife was not behind him.

"I saw her crawling on the ground, clearly in a lot of pain, her legs looked very bloodied," he recalled.

Despite sheltering beside a metal counter, the couple soon found themselves being stalked by one of the four gunmen from the al-Shabaab militant group, linked to al-Qaeda, who were purportedly sent to avenge Kenya's military incursion into neighbouring Somalia.

"I was looking at his face. He was young. He looked at me and he fired," Saville said.

But the gunman, now believed to have been a Norwegian citizen, Hassan Abdi Duhulow, was not yet satisfied. At point-blank range he repeatedly shot the couple.

That moment is among dozens of similar incidents in footage recorded that day by the many CCTV cameras in the shopping centre, much of it never before seen publicly.

It has been pieced together for a BBC film, Terror at the Mall, with much of the story narrated by those of different nationalities and faiths who survived the deadly attack. The footage paints an unflinching portrait of indiscriminate violence and terror - including the sight of the badly wounded Saville and Kang trying to reach out to one another as they lie on the floor behind the counter.

Watch: Raw: Graphic video of Kenyan Mall attack

Saville realised his wife "was clearly on the edge" an hour after they were shot, he said.

"She was shaking from what must have been a lot of blood loss - clearly in a lot of pain, clearly very scared," he recalled.

Amber Prior, who had been shopping with her 6-year-old daughter and 4-year-old son, was shot in the pelvis while hiding behind the meat counter.

"You're just lying there waiting to see when it's going to be you, when it's going to be your turn," she said. "I put my arms over my son and I put my leg over my daughter, then the footsteps got closer and the shooting began."

As she lay bleeding on the floor for more than half an hour, too terrified to move, others around her died.

Eventually, the gunmen returned to ask if any children were still alive.

Previously unseen CCTV footage shows the extraordinary moment when Prior managed to stand up, despite her injuries, and beg for the release of her children, who were unhurt.