President Uhuru Kenyatta has promised support for victims of the fire in Gikomba.
Uhuru has also assured thorough investigations and measures to prevent similar incidents in future.
At least 15 people died while 60 were injured in the fire that broke out at about 2.30 am.
It started at a section that deals with timber and second-hand clothes near Kamukunji.
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The following is the statement the President issued on Thursday:
"Fellow Kenyans,
This morning, we woke to the terrible news that a fire had broken out in Gikomba. In the hours since, the tragedy has deepened: Kenyans have lost loved ones; many victims, some of them young children, remain in critical condition in hospital.
My thoughts and prayers go out to the victims and to their families.
Prayer will be followed by action: we will support victims and their families through this difficult time; we will fully investigate the cause of the fire; and we will work to make sure that no such tragedy recurs.
The national government and Nairobi County will sit together for a full review of our emergency services, and our disaster preparedness. We owe the victims, and the people of Nairobi, a clear, credible plan to end these fires.
Let me thank St John’s Ambulance, and the other emergency services and response teams, as well as the hospitals which took in victims, chief among them the Kenyatta National Hospital. Your skill and speed saved lives this morning. Thank you.
May God bless and keep the souls we have lost; may he hasten the recovery of the injured; and may He grant those whose loved ones have been touched by this tragedy the grace to endure."
Leaders who have sent condolence messages include ODM's Raila Odinga, Senator Johnson Sakaja and Woman Representative Esther Passaris.
Raila said:
"My very sincere condolences to those who have lost friends and family in the Gikomba fire tragedy. I wish quick recovery to those in hospital."
Nairobi Senator Johnson Sakaja at the scene of the fire in Gikomba that left at least 15 dead, June 28, 2018. /COURTESY
On Twitter, Passaris wrote: "The departmental heads from the County Commissioner's office, the Fire Department, Disaster Management, County Trade and market leadership need to explain to the public what measures they put in place to counter such fires. #EnoughIsEnough #GikombaFire."
Sakaja demanded for prompt action by the DCI so there are no other fires at Gikomba market.
"We like the work being done by the DCI. We call for the same zeal to be used to address the fires at Gikomba," he said.
"It is a shame that Nairobi leaders keep coming here when there is a fire. We will find a lasting solution because the losses incurred here must come to an end."
The Senator asked the public to donate blood at Kenyatta National Hospital and other facilities for those admitted.
