A massive fire engulfed Nairobi’s Jomo Kenyatta International Airport on Wednesday, stranding hundreds of travelers at the busiest airport in East Africa. At least two people are being treated for smoke inhalation, though no serious injuries were reported. The cause of the fire is not yet known, but one passenger told Reuters that he heard two small explosions prior to it. The fire erupted at 5 a.m. at the immigration section of the arrivals hall and has since wiped out the area. Transport Secretary Michael Kamau said no flights had landed or departed since the fire broke out. Wednesday marks the 15th anniversary of the U.S. Embassy bombings in Nairobi and Dar es Salaam, Tanzania, but there were no immediate signs of terrorism in the fire.