JOHANNESBURG-- At least 12 people, including four children, have died as a result of a horrific accident in which a bus carrying 60 passengers overturned near Ngcobo in Eastern Cape province, the authorities say.

The bus driver also died in the accident in which the bus overturned Wednesday on the R58 highway, about five kilometres outside the town of Ngcobo while it was en route from neighbouring Gauteng Province to Mthatha in Eastern Cape Province.

Thirty-five people were taken to hospital and helicopters were used to ferry the critically injured patients.

Parts o the bus had to be cut to enable some passengers to be freed from the wreck.

Officials at the scene fear that the death toll may rise as some of passengers suffered serious head injuries.

The cause of the accident is not yet known.

Eastern Cape Health Department spokesperson Sizwe Kupelo said the department is doing all it can to clear the scene and urged motorists to drive cautiously on the roads.

Rescue efforts are continuing. Our workers are using jaws of life (cutters). We have three patients who are still trapped, I can confirm that all the three are still alive," said Kupelo.

"So far, the number of deaths has gone to 11. We are going to use a tow truck to move the wreckage so as to check if there are any survivors or any bodies under the wreckage."