China's three biggest airlines reduced about 70% of their capacity in February, data showed on Wednesday, as they grappled with the plummeting demand caused by the coronavirus epidemic.

China Southern Airlines and China Eastern Airlines each reported a 73% drop in February passenger capacity from a year earlier. Air China, the country's flag carrier, cut about 68% of capacity.

Passengers carried in February plunged more than 80% for all of the three airlines, while load factors for Air China and China Eastern came in better than China Southern at a touch above 50%.

Load factor for China Southern in February was at 47.11%, representing a decrease of 38.11 percentage points.

Both China Eastern and China Southern warned investors of the uncertain impact from coronavirus outbreak. All of them said they would further optimise capacity and step up cost-cutting.