Foreign forensic investigation teams joined their Kenyan counterparts on Wednesday (September 25) as they began examining the Westgate Shopping Mall in Nairobi, where the Somali Islamist militant group al Shabaab claimed to be responsible for the killing of dozens.

Armoured personnel carriers were seen driving away from the mall after Kenyan forces had gained full control of the complex, allowing the task of forensic investigation to begin after a four-day stand-off

U.S., British and Israeli agencies are helping Kenya investigate the attack on the mall that killed at least 72 people and destroyed part of the complex, officials said on Wednesday.

Speaking after a team of German police, part of the forensic investigation team, was seen walking towards the complex, the British High Commissioner to Kenya, Christian Turner, told reporters outside the mall that safety was still the paramount concern.

"As you know the current situation is that the current phase is to try and ensure that the building is safe and secure so that then the really detailed police work can begin to secure the crime scene and gather the forensic evidence," he said.

"I think from what I've been told there is a clear need to manage expectations. This could take some time," he told local media.

"We all want answers, we all want to know who's responsible for this brutal, cowardly and unconscionable act, but we now need to let the professionals do their job," he added.

Turner later said speculation over the precise series of events leading up to and during the attack was futile, and that professional investigators should be left to do their jobs.

Presented by Adam Justice

Read more: