(Reuters) - South Africa's logistics firm Transnet said on Tuesday it had suspended operations at some of its ports due to strong winds and waves which have lashed parts of the country, setting back efforts to clear backlogs.

The country's coastal regions, especially the Western Cape, have experienced disruptive rains and violent winds causing damaging waves since Sunday.

State-owned Transnet, which was already battling to clear port backlogs caused by under-investment in equipment and maintenance, impacting trade, said operations at four of its seven ports - Cape Town, Saldanha, Port Elizabeth and Ngqura - have been affected by bad weather.

"Strong winds reaching 35-50 knots and high sea swells exceeding 3.5 meters have led to shipping movements being suspended at some ports for safety reasons," Transnet said in a statement.

No major incident had been reported by Tuesday, Transnet added.

On Tuesday, the South African Weather Service also warned of damaging waves around Durban on the east coast, where the country's biggest port and one of the busiest in Africa, is located.

(Reporting by Nelson Banya; editing by David Evans)