The search for schoolchildren swept away in floods in South Africa's Eastern Cape province has resumed after being halted overnight, officials have said.

The children were on their way to school in the town of Mthatha when their bus was carried away in flood waters as it was crossing a bridge on Tuesday morning.

Officials said three students were later rescued, but it was unclear how many pupils were on the bus, which has since been found on a riverbank with no-one inside.

An unconfirmed report by private TV station Newzroom Afrika says the bodies of 10 children and the driver have now been found further downstream.

Public broadcaster SABC reported that the three children who were rescued on Tuesday were found clinging to trees.