South Africa declared a national disaster on Monday after heavy rains left seven of its nine provinces flooded, destroying roads and bridges and leaving farmers suffering losses.

The national weather service predicts that the heavy rains will persist, a statement from the presidency said.

The government has "declared a national state of disaster to enable an intensive, co-ordinated response to the impact of floods," the statement said, but gave no indication of casualties.

It said the heavy rains were brought by the La Niña global weather phenomenon, which occurs in the Pacific Ocean.

"These conditions demand the provision of temporary shelters, food and blankets to homeless families and individuals and the large-scale, costly rehabilitation of infrastructure," the statement added.