At least 49 people have died in South Africa after heavy rains caused major flooding Eastern Cape province, officials said on Wednesday.

The largely rural region, which stretches from the Indian Ocean into high inland mountains, has been battered by heavy rain and snow since the weekend.

Much of South Africa has been struck by heavy rainfall and bitterly cold conditions in the past days.

"We have never seen this kind of combination of snow and torrential rains in winter simultaneously," Eastern Cape premier Lubabalo Oscar Mabuyane told reporters.

Schoolchildren among the dead

Among those who perished were four children on a school minibus that was swept away by the waters, provincial authorities said.

"Sadly, four of those learners have been confirmed to be deceased, together with the driver and the conductor of the minibus taxi," Mabuyane said. 

"Four learners are still missing and are still being looked for," he continued, adding that three others had been found alive.

Officials did not provide additional information about the other victims, saying the situation is evolving.

Eastern Cape 'never experienced' such disasters

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

"Now we are busy with the rescue operation. So we are trying to get figures, our people out of that situation, dead or alive," Mabuyane said. 

He told public broadcaster SABC News earlier 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," Mabuyane added.

Hundreds sheltering from cold

Images from the remote area have shown informal settlements under water, as the disaster has flooded homes, displacing residents.

Provincial officials reported significant damage to infrastructure, including power and water supply.

Hundreds of families have sought shelter from the cold in community centers.

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

Edited by: Zac Crellin