ER24 spokesman Russel Meiring said that ER24 paramedics‚ along with several other services‚ were on the scene treating and triaging the injured.
"Initial reports from the aircraft crash in Wonderboom [say it] has left allegedly 20 people injured, at least one critically", ER24 tweeted.
The aircraft, a Convair 340 (ZS-BRV) was taking off from Wonderboom airport.
Mandatory fire evacuations lifted in Goleta
So keep our firefighters in mind - those we've lost in the past and those fighting fires now and for the rest of the summer. About 750 people have been evacuated from the communities of Holbrook, Hilt, Colestin and Irongate Reservoir.
Local emergency services posted a picture on Twitter showing passengers being helped out of a plane in a grassy field.
"We are not sure what happened at this stage", Rosella Passier, Aviodrome's marketing manager, told French news agency AFP.
The plane, which had been expected to arrive at the Aviodrome on Jul 23, "crashed in South Africa during take-off on a test flight", it said.
Meiring said there were two air ambulance helicopters on the scene.
United Kingdom nerve agent poisoning: Murder inquiry launched after woman dies
Sturgess originally collapsed at an address in Amesbury on June 30 and was taken to the hospital, police said . Sturgess died at Salisbury District Hospital , the same facility that nursed the critically ill Skripals.
"There are critical patients‚" Loubser said.
The plane was marked Martin's Air Charter, but no information was immediately available about the air company.
"A statement with further details will be issued tomorrow", said Kabelo Ledwaba, spokesperson of the South African Civil Aviation Authority.
Chris Sutton's verdict on France vs Uruguay and Brazil vs Belgium
They have the world's best centre-back, Diego Godin, in exceptional form. I for one think they can win the entire tournament.