As many as 20 people were injured when an aircraft crashed north of Pretoria in South Africa on Tuesday. At least one of the injured is in a critical state, South African emergency medical service ER24 tweeted.

The plane crashed in Wonderboom, an area just north of Pretoria, Times Live reported. The crash took place at an unspecified time in the afternoon, about 8 km east of Wonderboom Airport. There is no information about how many people were on board the plane.

“Initial reports show that approximately 20 people had sustained injuries ranging from minor to critical,” ER24 spokesperson Russel Meiring said. “Paramedics are treating the patients and will thereafter transport them to nearby hospital for further treatment.” He added that emergency helicopters are at the spot and could evacuate more injured persons.