The mid-air incident between local carrier Safarilink and the 99 Flying training school occurred Tuesday morning, Kenyan authorities said.
Nairobi police Adamson Bungei confirmed the deaths to AFP via text message without providing further details.
An earlier police report seen by AFP said the passenger plane “requested to turn back for landing” after the collision.
Safarilink said in a statement that the plane, with 44 people on board, was heading for Diani along the Kenyan coast when it “experienced a loud bang soon after take-off”.
All passengers and crew onboard the aircraft were unharmed in the accident, it said.
“The relevant agencies have been notified and together with Safarilink Aviation are investigating,” it said.
99 Flying School confirmed “an incident this morning” in a phone call with AFP but declined to give more information.
The training school caters for “private, commercial and airline sectors”, according to its website.
The Kenya Civil Aviation Authority said investigations had started to establish the cause of the accident.
Safarilink flies to 18 destinations in Kenya, neighbouring Tanzania and tourist magnet Zanzibar, according to its website.
AFP