Johannesburg - An unusually heavy snowfall that blanketed large parts of South Africa snarled transport on Tuesday, halting trains and leaving thousands of motorists stranded after highways closed.

The winter storm also brought high winds that played havoc with shipping and delayed air transport. The military dispatched a helicopter to pluck crew members from a cargo ship that ran aground off the east coast.

Parts of South Africa usually receive a dusting about once or twice a year but the storm that hit large parts of the eastern half of the country on Monday and Tuesday dumped up to 60 cms (2 feet) in some areas.

"Snow is not unheard of but it is usually not this extreme," said national weather service forecaster Karl Loots.

Transport authorities shut sections of major highways, including a heavily traveled route between Johannesburg and the main east coast city of Durban.

Snow is expected to fall in many parts of the country on Wednesday. The commercial centre of Johannesburg has avoided it.