(CBS News) NAIROBI, Kenya -- Five days after the terrorist attack in Nairobi, Kenya, more bodies were pulled from beneath the rubble of the Westgate Mall Wednesday.
New video released by the Kenyan government shows the full extent of the destruction.
Three floors collapsed after a fire and a series of explosions crippled part of the shopping complex. It was still smoldering Wednesday.
Forensic teams from the United States and Europe joined the investigation, sifting through the rubble and gathering evidence.
Bomb disposal teams from the FBI began fingerprint, DNA and ballistic analysis to help determine the identities of the victims and the al-Shabab gunmen.
Government officials would say little about the attack, other than it appeared to be well planned.
The massive amount of firepower suggests the militants may have rented a store and stashed their weapons inside the mall ahead of the attack.
We asked officials whether they could comment on indications that the militants may have hired a shop and had been planning the attack for several months.
"Whether the terrorists hired a shop in the mall is a rumor we have had just like you, and we will treat as such until the forensic exercise and any other investigation taking place prove it otherwise," government officials told CBS News.
Flags were flown at half staff to mark a three-day period of mourning as Kenyans continue to hold funerals for the dozens of victims killed in the attack.
On Wednesday night, for the first time, the leader of al-Shabab in Somalia confirmed his group was responsible for the massacre in retaliation for Kenya's military involvement in Somalia. He warned there would be more violence to come unless Kenya pulls its troops out of Somalia.