The Kenyan authorities say nine people have been arrested in connection with the attack in an upmarket neighbourhood of the capital, Nairobi.
On Wednesday night, the police announced that the death toll from Tuesday’s siege at the DusitD2 hotel and business complex had risen from 14 to 21.
Six more bodies were found at the scene of the hotel siege, and a policeman had died of his injuries, the police said.
The Red Cross says 14 people are still missing.
An unnamed British casualty is among those still being treated in hospital.
Meanwhile, the Kenyan media is reporting that the wife of one of the suspected attackers has been arrested in Kiambu county just north of Nairobi.
Neighbours told the Standard newspaper that the couple was secretive and said the woman had put their household property up for sale the day before the attack.
The Kenyan authorities said all the terrorists were killed by the security forces in a well-co-ordinated operation.
But they added that a major investigation was now underway to track down those who helped organise the attack.
Somalia-based Islamist group al-Shabab said it was behind the attack, which triggered a 19-hour security operation.