By Sunday morning al-Qaeda linked militants were still holding an unknown number of hostages at an upmarket shopping mall in the Kenyan capital.
Security forces were locked in a stalemate with the Somali Islamist al-Shabab militants who've claimed responsibility for the attack.
At least 39 people have been killed. They include two Canadians and two French nationals.
The U.S. said several of its citizens were among the wounded. Kenya's president says some of his own relatives are among the dead.
The bloodshed began on Saturday when gunmen stormed the Westgate shopping mall in Nairobi.
As the stand-off continued relatives of hostages feared to be inside the building were keeping a vigil nearby waiting for the next move by security forces.