A military helicopter hovers above the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Zhang Chen)

 

Soldiers arrive at the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Zhang Chen)

 

A military armored vehicle arrives near the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Zhang Chen)

 

Soldiers take positions outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/George M. Mulala)

 

A wounded man arrives at the Aga Khan Hospital in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Li Jing)

 

A wounded man arrives at the Aga Khan Hospital in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Li Jing)

 

A wounded man arrives at the Aga Khan Hospital in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Li Jing)

 

The body of a man lies on the ground outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/George M. Mulala)

 

A wounded man arrives at the Aga Khan Hospital in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Li Jing)

 

The body of a man is taken from the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/George M. Mulala)

 

Soldiers take positions outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/George M. Mulala)

 

A wounded woman is helped to safety outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/George M. Mulala)

 

People help a wounded man outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Fred Mutune)

 

The body of a man lies on the ground outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Fred Mutune)

 

People help a wounded man outside the Westgate shopping mall in Nairobi, Kenya, Sept. 21, 2013. At least 20 people have been killed and more than 50 others wounded when masked gunmen stormed a popular shopping mall in the Kenyan capital Nairobi and held shoppers hostages on Saturday. (Xinhua/Fred Mutune)