At least 11 people, including two children, were killed and another 34 injured after a bus crashed into a ravine in Peru, authorities said Sunday.

The accident happened on Saturday afternoon when a bus overturned and rolled 100 meters (330 feet) down a ravine in the Ancash region to the north of Lima, the National Institute of Civil Defense said.

The bus was heading to Lima from the northern region of La Libertad along the main Tayabamba highway.

"We have registered 34 injured and 11 dead after an accident in the Ancash region," said a Civil Defense statement.

Police and local residents worked until Sunday morning to try to free bodies from the wreckage.

The injured were taken to the regional hospital in Sihuas province.

Authorities said they were investigating what provoked the accident.

Road accidents are frequent in Peru due to speeding, poor road surfaces, lack of signs and minimal enforcement of rules by authorities.

In February, 20 people died when a bus crashed into a ravine in the northern town of Tayabamba.