The executioner: Caught on CCTV, the horrific moment Al Shabaab gunman took deadly aim at hostages in Nairobi mall massacre

• Terrorists caught by CCTV aiming at cowering hostages at Nairobi mall
• Masked man seen pointing gun inside bank at Westgate shopping centre
• Other images show women and children sitting among dead bodies
• Militants killed 67 people and injured 200 - with 71 still missing

This is the horrifying moment one of the terrorists in the Kenyan shopping centre attack levelled his gun at cowering hostages, ready to execute them. The attacker, wearing a camouflage jacket and facemask, points a handgun at customers in a bank as they lie under a counter with their hands around their heads. The CCTV pictures were taken inside the Diamond Trust Bank on the ground floor of the Westgate shopping mall in the early stages of the hostage crisis.

Terror at the mall: A gunman takes aim at the hostages as they lie face down inside a bank at the Westgate shopping centre during the terrorist attack

Another picture shows three fighters brandishing rifles at the entrance to the shopping centre, one of them apparently wearing a traditional Islamic robe and pointing at a figure cowering in the corner. In other images, women and children are shown on the roof of the building among the blood-stained bodies of the dead and injured. The group is thought to include families who were attending a cookery demonstration by a TV chef Ruhila Adatia-Sood, who was six months pregnant and died in the attack. They were eventually rescued by the Red Cross, who arrived with stretchers as the terrorists moved inside the building. For many it was their choice of hiding place that made the difference between death or survival. Some security camera footage shows gunmen raking toilet cubicles with gunfire, apparently after learning that people were hiding inside.

Horror on the roof: Women and children, thought to be part of the group attending a cooking demonstration, sit among bodies of the dead and injured

Sinister shadows: A CCTV image shows three armed terrorists entering a bank in the Nairobi shopping centre

Other attackers took the time to divide Muslims from non-Muslims after demanding that some recite the Shahada, the Muslim profession of faith. A man trapped inside the shopping centre told The Mail on Sunday he had a clear view of a woman brandishing a sniper rifle. Achebe Odida, 42, a glass engraver, described how he hid under the counter of a mobile phone shop as the shooting began and raised his head to look out of the window. ‘I saw a woman wearing a black headscarf and a black shawl over a pink top and black trousers,’ he said. ‘While shoppers were running and screaming through the mall, she moved slowly and calmly to take up position behind a pillar. She looked like a Somali woman, tall and slender with dark skin.’ He saw her brandishing the rifle as if to take aim, but did not see her shooting anyone. The Kenyans have yet to announce how many terrorists were involved in the atrocity. They say five were killed in the shopping centre and it is unclear whether the eight people they currently have under arrest were detained at the scene or elsewhere.

Mourning: People light candles during a memorial service in front of the shopping centre

Prayer: A father lights candles with his son during the 24-hour vigil

In memory: Kenya Defense Forces soldiers pay tribute to victims of the terrorist attack

The siege developed into a hostage drama with Al Shabaab claiming civilians were being held but if there were hostages, it is unclear what became of them. In one section of the shopping centre, three floors collapsed, making the search for them difficult and dangerous. The collapse was caused by Kenyan soldiers firing rocket-propelled grenades into the building, according to a senior official, raising questions about the effectiveness of the rescue operation. Soldiers and police were said to have been arguing over who was in charge. Some of the heroes of the operation were private security guards and relatives called by those hiding inside. Presidential spokesman Manoah Esipisu did not comment on the cause of the collapse but said structural engineers were examining the building. The Kenyan authorities have insisted that all the dead are accounted for, although the Red Cross says it has reports of 71 missing, as well as the official tally of 67. The Foreign Office said another Briton was among the dead, putting the total back up to six, after one man was discovered to have been Kenyan.