Members of the public stand in front of the Jomo Kenyatta International Airport as it goes up in flames in Kenya's capital Nairobi, Aug. 7, 2013. Reuters/Stringer

East Africa's busiest air transit hub shut down temporarily on Wednesday after flames engulfed the international arrivals hall and immigration processing center at Jomo Kenyatta International Airport in Kenya's capital city of Nairobi.

The fire, which erupted around 5 a.m. local time, has been contained. Investigators are working to discover the cause of the inferno, which sent massive black plumes of smoke billowing over the capital. International flights have been suspended indefinitely, leaving hundreds of outgoing passengers stranded in Nairobi, with many incoming passengers being diverted to the coastal city of Mombasa, about 300 miles to the east.

Stephen Gichuki, director of the Kenyan Airports Authority, told the Associated Press that officials are working to resume international flights.

"We reassure international and local travelers that arrangements are being put in place to restore normal operations," he said. "The airlines are working to assist stranded passengers and advise them on the measures being put in place to resume services at JKIA."

Domestic flights are set to resume by the end of the day, according to the Kenyan newspaper Daily Nation. "We expect cargo and domestic services to resume from this airport this afternoon. They will operate from the cargo terminal," government spokesman Manoah Esipisu said.

Early reports indicated that the fire resulted in no injuries, but Standard Digital, a Nairobi newspaper, later quoted Titus Naikuni, Kenya Airways' CEO, confirming that two people -- one of the airline's employees and one passenger -- had been admitted to a hospital for smoke inhalation.

There were no immediate indications that the flame was sparked intentionally, though the timing of the incident has aroused suspicions. Wednesday marks the fifteenth anniversary of al-Qaeda perpetrated bombings of American embassies in Kenya and Tanzania.

Furthermore, global travelers were already on high alert after the U.S. closed down 20 of its embassies and consulates in North Africa and the Middle East this weekend, citing increased risk of terrorist attacks based on intelligence gleaned from recent phone conversations between top al-Qaeda figures. In sub-Saharan Africa, four American embassies -- in Madagascar, Mauritius, Rwanda and Burundi -- remain closed. The U.S. embassy in Kenya is open.

Some passengers recall hearing explosions as the fire began. "I was waiting for my flight around 5 a.m. when I heard two explosions, as if from gas cylinder or electricity fault," said one Kenyan traveler, according to Reuters. "Within minutes, the entire airport was secured by police and Kenya airport authority personnel, who ordered everybody out of the airport."

In the aftermath of the blaze, Nairobi's emergency response capabilities have already faced heavy criticism. About four hours passed before the fire could be contained. Emergency response vehicles struggled to reach the airport amid heavy traffic, and the Daily Nation reported that some fire hydrants had failed.

Following the incident, shares in Kenya Airways Ltd. fell by 2 percent and business leaders voiced concerns about the immediate affect on national exports. The entire East African region is bracing for the long-term effects of this disaster as investigators work to uncover the cause of the fire.