Kenyan police said 21 people were confirmed dead.
Two individuals have been arrested over an attack at a Nairobi hotel complex on Tuesday, said Joseph Boinnet, Kenya's Inspector General of Police at a press conference.
Boinnet also revised the number of deaths from 14 to 21.
"This is the final tally as of this evening: six other bodies were found at the scene, and one police officer succumbed very sadly to his injuries when undergoing treatment. Five terrorists were eliminated," he said.
The UK's High Commissioner to Kenya, Nic Hailey, released a video statement on Wednesday morning, confirming the death of a British man.
The man was identified as Luke Potter, the Africa Programmes Director of the UK charity, Gatsby, who announced his passing on their website.
“Luke was respected by all he worked with, bringing huge drive, determination, a relentless work ethic, and a thirst for new ideas to every project. He brought a calm head and his unique sense of humour to every situation. He was deeply committed to his work, to his teams, to Gatsby and to development in Africa. He was our colleague and our friend,” the statement read.
They went on to say that Potter devoted 10 years of his career to help some of the poorest and most vulnerable people in the world. At Gatsby, he spent three and a half years building up their team in Kenya and was pivotal in their forestry programmes around the region.
The organisation expressed their grief and condolences to Potter's family, partner and daughter and requested privacy for his loved ones and colleagues during this difficult time.
The attack on the DusitD2 compound began shortly after 3 p.m. local time (1 p.m. CET) on Tuesday.
Several people inside the hotel at the time of the attack posted messages to social media pleading for help.
Ron Ng'eno posted to social media several times, saying he was hidden in a bathroom at the hotel as gunfire was heard outside.
Contact was lost with Ng'eno shortly thereafter, when Ng'eno posted to say his phone was losing charge. "Please pray," he said.
In the early hours of the Wednesday morning, Ng'eno posted to Facebook to say he had escaped the scene, and he thanked Kenyan authorities for their work.
In a further post, he said he had returned home with family.
At least two groups of civilians remained trapped in the complex just before 7 a.m. on Wednesday, a first responder told Reuters, adding that gunfire had been ringing out from around dawn.
Somali Islamist group al Shabaab has claimed responsibility for the attack.
The militants from neighbouring Somalia have conducted many attacks on Kenya in recent years. The last big assault was in 2013 when al Shabaab killed dozens of people in a shopping centre, and later in 2015 when nearly 150 students were killed at a university.
Families search for loved ones
Families of people in the complex at the time of the attack have been rushing to the Chiromo morgue in search of loved ones.
One man, who only gave his name as David, told Reuters he had yet to hear from a relative in the hotel complex.
"I have been trying to reach him since yesterday when the incident happened... I spoke to him when the incident started around 3.30, when they started shooting... his phone went off around 4 p.m.," he said.
The family of one 35-year-old man collapsed in the courtyard after hearing that a body had arrived with his identification papers.
Another family arrived, demanding to see whether their relative was there but were told only police had access.
The Kenya Red Cross urged families searching for loved ones to call its "tracing line".