Thirty people have been killed when a passenger bus fell from a bridge and plunged into a river in central Kenya.

Police said the bus carrying an unknown number of people crashed on Sunday evening on a highway from Meru to the capital, Nairobi.

The bus “must have developed brake failure, because it was at a very high speed when the accident happened”, senior police official Rono Bunei said.

Officer Bunei said the death toll grew to 30 from 24 overnight, with others hospitalised with injuries.

The accident is the latest in a series of deadly crashes in Kenya – and across the wider East African region – where roads are often narrow and police blame speeding drivers for crashes.

At least 20 passengers were killed on July 8 in a crash along the highway from Nairobi to the coastal city of Mombasa.