Kenyan police chief Joseph Boinnet said a suicide bomber had been involved in an attack on a Kenyan hotel on Tuesday.

"That (attack) began with an attack at I&M bank with an explosion that targeted three vehicles in the parking lot and a suicide bomb," he said.

Police have secured six floors out of seven at the Dusit D2 hotel in the complex that militants attacked, he said. A Reuters reporter at the scene said there was a heavy outbreak of gunfire while the police chief was speaking at a separate location.