Heavy rainfall, snow and cold winds have affected areas of the Eastern Cape province, with most of the country experiencing brutal winter weather conditions since last week.

Floods caused by torrential rains in the OR Tambo district claimed nine lives, a statement from the local government said, raising an earlier toll of seven.

The search for missing children aboard a minibus taking them to school that was swept away by a flood near the city of Mthatha was ongoing Wednesday, it added.

Khuselwa Rantjie, spokeswoman for the Eastern Cape Provincial Government, told AFP she could not confirm how many children or adults were on the bus.

South African TV station Newzroom Afrika with a reporter near the scene said that that 10 bodies were discovered on Wednesday afternoon. Several outlets reported that the bus could carry up to 22 people.

Separately, three children were rescued after spending hours in trees to escape rising waters.

- Lack of resources -

Several hundred people have been displaced since Monday, according to the government, mainly from OR Tambo and Amathole districts, with some relocated in schools and town halls.

The local authority said it was providing hot meals and essentials to those housed in temporary shelters with support from several government agencies.

Eastern Cape top official Oscar Mabuyane told public broadcaster SABC News that only one helicopter was available in the province.

"We need more resources," he said. "We have never experienced disasters like this but now it's inevitable with climate change and global warming."

The "relentless downpours" also caused landslides and "significant damage to property and infrastructure", the local government added.

President Cyril Ramaphosa said in a statement that harsh winter conditions "remain life-threatening" adding that emergency services, including support from the National Disaster Management Centre, were "giving the requisite attention to crises as they unfold".

He called on South Africans "to display caution, care and cooperation as the worst impacts of winter weather take effect".

South Africa's national weather service has warned that severe and extreme winter weather conditions would persist until at least the middle of this week.

Snow and heavy rainfall are common during winter in South Africa but the country is also highly vulnerable to the impacts of climate variability and change, which increases the frequency and severity of drought, floods and wildfires, according to the Green Climate Fund.