Story highlights Source tells CNN that authorities think one person went through hole in plane and fell to death

The explosion rocked Daallo Airlines Flight 3159 soon after it took off from Mogadishu

Initial tests of the damage are positive for explosive residue, a knowledgeable source says

Nairobi, Kenya (CNN) An explosion rocked a commercial plane after it set off above East Africa on Tuesday, injuring two people before the pilot landed safely, a passenger said.

Somali authorities later discovered a body near Mogadishu they believe fell from the Daallo Airlines plane.

Late Tuesday night, a source with knowledge of the investigation told CNN that Somali authorities confirmed one passenger had been blown or ejected out of the hole created by the explosion. Somalia's National News Agency reported that one passenger died after falling from the plane.

Pictures from the ground showed a hole in one side of the airliner, just above its wing and slightly smaller than one of its doors.

Initial tests of the damage on Flight D3159 came back positive for explosive residue, a source with knowledge of the investigation told CNN.