LIMA (AFP) - At least 48 people were killed in Peru on Tuesday (Jan 2) when their bus plunged around 100m over a cliff after colliding with a truck, police said.

The incident "left at least 48 victims" dead, a police statement posted on the Interior Ministry's website said, revising earlier tolls of at least 25 dead, and then 36. There were 53 passengers on board.

The bus was travelling from Huacho, 130km north of the capital, to Lima when it went off the road about midday.

It plunged 100m and landed upside down on rocks at the edge of the sea.

A police helicopter winched some rescue workers down to the wreck of the blue bus while others made the precarious journey down on foot with the assistance of ropes.

The Navy sent a patrol boat to assist the rescuers trying to get everyone out before the tide rose.

Maria Elena Aguilar, director of Alcides Carrion Hospital in El Callao, said her facility received five patients with multiple injuries.

The accident took place on a coastal highway about 45km north of the capital Lima. The Pasamayo highway is only used by trucks and buses, as cars travel a different route.

It is a dangerous sea-hugging road where fog is frequent and high humidity can make the roadway slippery.

The bus driver had a lot of experience and was working with an assistant, said Luis Martinez, a representative of Transportes San Martin de Porres, which owned the bus.

Martinez could not confirm whether the driver had been killed or injured, but added that the bus underwent a mechanical check before leaving Huacho.

More than 2,500 people died in traffic accidents in Peru in 2016, according to official figures.