Global Aviation, Four seater-Plane flying from Nigeria to Gabon Gone Missing

Global Aviation, Four seater-plane flying from Nigeria to Gabon via Cameroon has gone missing.  The plane took off from Kano Airport at about 6pm on Monday June 23^rd 2014 and was billed to make a stopover  at Doula Cameroon before continuing to Gabon to arrive at 11pm but Cameroonian Aviation authorities said it never arrived at Doula, Only an American pilot was on-board.
And The Gabon Aviation authorities said that the last contact they had with the plane was when it was in Mongo which is a 2-hour flight from the Cameroonian economic capital.
Search & Rescue operation has so far not yielded any result.