International experts – including a team from Scotland Yard – are helping the Kenyan authorities as they seek to establish the identities of the militants who carried out the bloody, four-day assault.
Interior minister Joseph Ole Lenku said it was still not known whether there were any Britons or Americans among the militants or whether any of them was a woman.
“In our previous briefings, we indicated that there was no indication to suggest that there is a woman terrorist, but going forward we are all hearing possibilities and information – including from volunteers from the public,” he told reporters.
“We want to again request you to allow the forensic experts to determine whether that is true.”
The persistent suggestion that a woman was involved has led to speculation that it could be the British terrorist suspect Samantha Lewthwaite – who was married to the 7/7 bomber Jermaine Lindsay.
Dubbed the “White Widow”, Lewthwaite is known to be in East Africa and is wanted by Kenyan police over alleged links to a terrorist cell that planned to bomb the country’s coastal resorts.
Mr Lenku said the forensic teams – including experts from the US, Israel, Germany Canada and Interpol – were examining fingerprint, DNA and ballistics evidence in the hunt for clues.
President Uhuru Kenyatta declared on Tuesday night that the Islamist militants from the Somali-based al-Shabaab group who carried out the attack had been “defeated” as he announced three days of national mourning.
The Kenyan authorities have said that 61 civilians – six of them British – and six members of the Kenyan security forces were known to have died during the stand-off. Five terrorists were also killed, while ten suspects remain in custody in relation to the incident.
Citizens from France, Canada, Trinidad, the Netherlands, Australia, Peru, India, Ghana, South Africa and China are amongst the dead.
Mr Lenku said that he did not expect the civilian death toll to rise significantly, although there may be more terrorists buried in the rubble of the Westgate Mall, after three floors collapsed during the final stages of the siege.
As Kenyan troops combed through the wreckage, sporadic bursts of gunfire could still be heard from the mall.
A government spokesman said any shooting was from Kenyan troops, who were acting protectively, and the terrorists’ resistance had ended.
“During sanitisation, once you take control of the place, if you go to a room where you haven’t visited before, you shoot first to make sure you aren’t walking into an ambush,” he said.
“But there hasn’t been any gunfire from the terrorists for more than 36 hours.”
Yesterday, the Islamic terrorist group that attacked the mall said foreigners were a “legitimate target” and confirmed witness accounts that gunmen tried to let Muslims go free while killing or taking the others captive.
In an e-mail exchange with the Associated Press news agency, al-Shabaab said the gunmen “carried out a meticulous vetting process” so the Muslims would not be harmed. Witnesses have said they rounded up people, asked questions about Islam that a Muslim would know, and told the Muslims to leave the mall.
“The Mujahideen carried out a meticulous vetting process at the mall and have taken every possible precaution to separate the Muslims from the Kuffar (disbelievers) before carrying out their attack,” al-Shabaab said. The group had threatened retaliation against Kenya for sending its troops into Somalia.
Asked if al-Shabaab intended to kill foreigners in the mall attack, the group said “our target was to attack the Kenyan government on its soil and any part of the Kenyan territory is a legitimate target . . . and Kenya should be held responsible for the loss of life, whether foreigners or local”.
Many of those killed in the attack were Kenyans.
Al-Shabaab controlled much of Somalia, which borders Kenya to the east, for several years, including most of the capital Mogadishu.
African Union forces pushed the al-Qaeda-affiliated group out of Mogadishu in 2011 and Kenya sent in troops that year, further squeezing the group into smaller territory in Somalia’s south. Al-Shabaab has responded with attacks against government targets in Somalia, usually suicide bombings, but has also set off bombs at a college graduation ceremony in Mogadishu, at restaurants and other locations, killing Muslim civilians.
Asked if the separation of Muslims from non-Muslims represented a change in tactics, the group insisted it “has never deliberately targeted Muslims”.
“Our targets have always been disbelievers, invaders and the apostate governments officials/troops who are allied with them,” the e-mail said.
The attackers tried to claim the destruction was not their fault. The group claimed that a Kenyan assault team carried out “a demolition” of the building, burying 137 hostages in rubble and also used chemical weapons. A government spokesman denied the claims.
He said the collapse of three floors in the mall was caused by a fire started by the terrorists.
“Al-Shabaab is known for wild allegations and there is absolutely no truth to what they’re saying,” he said.