* Africa fourth-busiest airport using make-shift structures
* Minister says terrorism, arson, sabotage ruled out
NAIROBI Oct 4 A fire that gutted the arrivals building at Kenya's main airport in August was caused by an electrical fault, not terrorism, the government said on Friday.
Kenya is still on edge, two weeks after Islamist militants killed at least 67 people in a raid on a Nairobi shopping mall, but the airport fire was not an act of violence, cabinet secretary Michael Kamau told staff there.
"The fire was an accidental incident ... that started from an electricity distribution board," Kamau said.
The date of the fire on Aug. 7 coincided with the 15th anniversary of an al Qaeda attack on the U.S. embassies in Nairobi and Dar es Salaam and investigators said at the time they could not rule out terrorism.
"Nothing to do with terrorism, no sabotage, no arson," Kamau said during a visit to inspect repairs at the airport.
"We should not be ashamed to tell the world. If it was terrorism, we would have said so," he added.
The assault on the Westgate mall was the worst militant strike in Kenya since embassy bombing in 1998. Somali's al Qaeda-linked militants al Shabaab have claimed responsibility.
A formal report on the airport fire will be released soon, Kamau said. The investigations into the blaze included local and foreign agencies, including the FBI.
The fire was a blow to Kenya at the start of the peak tourism season, disrupting travel at Africa's fourth-busiest airport. The horticulture industry, a major foreign exchange earner for east Africa's biggest economy, was also affected.
Kenya expects a temporary passenger terminal to be ready by the end of the year, and will accelerate work on a new terminal already under construction, officials have said.
Kenya Airways' says the fire cost its about $4 million in revenue.
Other airlines flying out of Nairobi airport include Emirates, British Airways, Etihad, South African Airways, Ethiopian Airlines and Rwanda Air. (Reporting by James Macharia; Editing by Robin Pomeroy)