A fire engulfed Kenya's main airport on Wednesday forcing the closure of a vital travel and trade gateway to east Africa.

Flames from the inferno lit up the early morning sky, and the intense heat repeatedly drove back firefighters. A huge plume of black smoke billowed from the airport buildings, but there were no immediate reports of casualties or injuries.

Hundreds of passengers were stranded outside Jomo Kenyatta International Airport in the capital Nairobi, which was cordoned off to keep the public out after the fire started early in the morning in the arrivals and immigration area, officials said.

The cause of the worst fire in record at east Africa's busiest airport was not yet known.

"We are still fighting to contain the fire. Investigations will start immediately after," Michael Kamau, cabinet secretary for transport, told reporters at the airport.

"The fire started at a very central part of the airport and this made access difficult. But we have closed the airport indefinitely as we try to contain the fire."

One passenger at the airport said he heard two small explosions from the international arrival area, then sirens.

"I was waiting for my flight around 5 a.m. (0200 GMT / 10:00 p.m. Tuesday EDT) when I heard two explosions, as if from gas cylinder or electricity fault," said the passenger, a Kenyan who requested anonymity.


"Within minutes, the entire airport was secured by police and Kenya airport authority personnel, who ordered everybody out of the airport," he said.

The airport buildings were ravaged by the fire. Television pictures showed desks that had been reduced to charcoal inside the burned out terminal. The roof had partly caved in, and the floor was flooded with water from fire fighters.

Transport secretary Kamau said no plane had landed or departed since the fire started, and said he could not give any indication of when the airport would reopen. Airlines that wanted to take off without passengers have been allowed to do so, he said.(Reuters)