Fire gutted part of Nairobi's biggest market on Friday in what the government suspected was an act of arson.
Devolution Cabinet Secretary Mwangi Kiunjuri vowed stern action against those who might have started the fire at Gikomba market.
He said reports received so far by the government point at arson.
"From the initial reports that we are getting, we are saddened that they appear to point at foul play. The government has set in motion investigations into the cause of this fire to fully establish what caused it," the minister said in a statement to newsrooms.
"Let it be known that stern action will be taken on the culprits should the investigations establish foul play," added Mr Kiunjuri.
The CS also said the national and county governments are considering "reconstructing the market to make the structures permanent" as a measure of protecting businesses in the market against fires.
He added that Gikomba is a "very important market for such a big section of the city's population" and pledged that the government will not abandon the traders who suffered losses.