Kisumu Governor Anyang' Nyong'o on Tuesday inspected the county lands offices gutted by fire on Sunday afternoon.
Nyong’o said initial investigations pointed to arson.
"I condemn this incident and the culprits must be brought to book," he said.
The county boss had met with Nyanza regional commissioner Magu Mutandika and county commissioner Josephine Ouko before visiting the scene.
The three leaders discussed ways of beefing up security at Prosperity House. The fire was on its ninth floor.
The Governor Press Unit director, Aloice Ager, said preliminary evidence revealed a high possibility of arson.
Ager said a statement will be issued once investigations are completed.
"In the meantime, the county government requests the public to remain calm while the team carries out its work thoroughly and professionally to get to the bottom of this incident," he said.
The 3pm Sunday fire started from the Lands and Planning department.
The building houses Huduma Centre on the ground floor, county government offices and the county commissioner's office.
The fire destroyed office documents, stationery and computer accessories. There were no casualties.
Ouko said they received a call from officers manning the building that there was smoke emanating from the ninth floor. They immediately mobilised a response team, which speedily reached the venue to put out the fire.
She noted that because of the quick response, they prevented the fire from spreading.
The county commissioner further stated that the investigation team, which was also present at the scene, had begun looking into the matter.
The Kisumu county fire brigade rushed to the scene 15 minutes later and helped control the blaze within an hour.
(Edited by Bilha Makokha)
