Police and emergency officials in South Africa say at least 28 people are dead and at least 22 seriously injured after a bus swerved off a cliff and into a river in the Eastern Cape.

Officials had earlier released a higher death toll. A police spokeswoman, Zandra Wild, says the figure may change as police and rescue workers search the crash scene near the town of Cedarville.

An emergency services spokesman, Chris Botha, says the bus landed upside down in the river after it went out of control and plunged off an 80-meter embankment Tuesday.

He said a helicopter and ambulances were on hand to assist with the rescue effort.

South African media say about 80 people were believed to be on the bus.

Some information for this report was provided by AFP and Reuters.