MOGADISHU, Somalia (AP) — Officials at Somalia's civil aviation authority said Wednesday they had found no evidence so far of a criminal act in an explosion in an airliner which took off from Mogadishu's airport and returned for an emergency landing.

Investigators moved the plane from the runway to a private hangar. Foreign technical experts were involved in the inquiry, said Ali Mohamoud, an aviation official at the Mogadishu airport.

The pilot said he thought the blast was caused by a bomb.

Two passengers on board the flight that was headed to Djibouti in the Horn of Africa said they heard a loud bang, suggesting an explosion that left a hole in the passenger cabin.

Awale Kullane, Somalia's deputy ambassador to the U.N. who was on board the flight, said on Facebook that he "heard a loud noise and couldn't see anything but smoke for a few seconds." When visibility returned they realized "quite a chunk" of the plane was missing, he wrote.

The plane was headed to Djibouti when the blast happened minutes after takeoff. An official investigation is underway and a preliminary report will be issued later this week, officials said.

Although Mohamoud said that there were only two injuries, there were unverified reports that a person fell out of the hole.

Daallo Airlines said in a brief statement posted on its Facebook page that the Airbus A321 plane was operated by Hermes Airlines. It said the plane "experienced an incident shortly after take-off."

"The Aircraft landed safely and all of our passengers were evacuated safely. A thorough investigation is being conducted by Somalia Civil Aviation Authority," the Daallo statement said.

Officials reached Wednesday by The Associated Press at the carrier's Dubai office had no immediate further comment.

Hermes Airlines is based in Athens, Greece. Its main business is providing planes on a "wet lease" basis, meaning it leases insured planes staffed and serviced by its crew to other carriers. Its fleet includes four A321s and one Boeing 737, according to its website.

Mohamed Hassan, a police officer in Balad, an agricultural town 30 kilometers (about 18 miles) north of Mogadishu, said residents had found the dead body of an elderly man who might have fallen from a plane.

"I think it was a bomb," said the Serbian pilot, Vladimir Vodopivec, who was quoted by Belgrade daily Blic. "Luckily, the flight controls were not damaged so I could return and land at the airport. Something like this has never happened in my flight career. We lost pressure in the cabin. Thank god it ended well," the 64-year-old pilot said.

Somalia faces an insurgency perpetrated by the Somali Islamic extremist group al-Shabab, which is responsible for many deadly attacks across the nation.