Construction workers dig holes to erect barriers at the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

A woman carrying her child walks past the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

Women carrying children run for safety as armed police hunt gunmen who went on a shooting spree in Westgate shopping centre in Nairobi September 21, 2013. REUTERS/Goran Tomasevic

Cleaners work inside the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

Armed police search through Westgate shopping centre for gunmen in Nairobi, September 21, 2013. REUTERS/Goran Tomasevic

Attendants work in a shop selling shoes inside the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

Workers stand in a section of the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

People scramble for safety as armed police hunt gunmen who went on a shooting spree at Westgate shopping centre in Nairobi, September 21, 2013. REUTERS/Goran Tomasevic

Workers are seen near a perfume advertisement inside the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

A police officer tries to secure an area inside the Westgate Shopping Centre where gunmen went on a shooting spree in Nairobi September 21, 2013. REUTERS/Siegfried Modola

A security guard stands at the main entrance of the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

A child runs to safety as armed police hunt gunmen who went on a shooting spree at Westgate shopping centre in Nairobi September 21, 2013. REUTERS/Goran Tomasevic

Cleaners work inside the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

An injured policeman holds on to his wound as his compatriot searches through the Westgate shopping centre for gunmen in Nairobi, September 21, 2013. REUTERS/Goran Tomasevic

A shop attendant is seen in the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

Security officers secure an area inside Westgate Shopping Centre in Nairobi September 21, 2013. REUTERS/Siegfried Modola

A worker is seen near a shop at the food court area inside the reopened Westgate shopping mall, which was closed in the aftermath of an attack by militant gunmen in September 2013 that killed 67 people and injured many more, in capital Nairobi July 14, 2015. REUTERS/Noor Khamis

Armed police search customers taking cover inside a bathroom while combing through the Westgate shopping centre for gunmen in Nairobi, September 21, 2013. REUTERS/Goran Tomasevic