Spokesperson Russel Meiring says five ER24 services and others are working to extinguish the fire which broke out after the crash.
"We suspect that the plane was on its way to the Wonderboom airport", said Mahamba. "We have got about 20 patients with injuries ranging from serious to critical, including two people who were on the ground".
It was unclear how many people were on board the plane when it went down.
It had been due to fly to Aviodrome via east Africa, through Egypt, Croatia, Austria to the Netherlands.
"They are busy treating one of the pilots ... and he will be airlifted to a Netcare hospital", he said.
According to the Aviodrome's website, it cost 350,000 euros ($410,000) to make the plane "flight ready" and buy parts for the planned trip to Europe.