The flight carrying Madagascar's ousted president Marc Ravalomanana has been barred from landing in the country, an airline spokeswoman told AFP, thwarting his bid to end his three-year exile.
"The flight has been turned back from the Madagascar airspace," said Karin Murray, spokeswoman for SA Airlink, a unit of South African Airways.
An AFP correspondent on the plane said that the flight landed back in Johannesburg around 2:10 pm (1210 GMT), about four hours after it departed.
Peter Mann, a spokesman for Ravalomanana in South Africa, said that Madagascar's authorities had shut all of the country's airspace.
"What happened apparently was that the Malagasy regime... has closed Madagascar's airspace," he told AFP.
"This is an act of utter foolishness. It's highly dangerous" for the passengers on board, he said. "It sets the whole political process back enormously."