At least 80 people have been injured after a packed bus plunged down a ravine near Barcelona on Sunday.

The vehicle was carrying visitors home from Montseny Natural Park when it fell around 20 metres in Fogars de Montclus at around 4.43pm.

Of those hurt, at least seven are in a serious condition, while 18 suffered moderate injuries and 58 were assessed as having minor injuries.

Search teams were continuing to check the surrounding terrain on Sunday night amid fears passengers could have been thrown from the vehicle.

The bus left the BV-5114, the main road through Montseny, at approximately 4.43pm. No other vehicle was involved, and the cause remains unknown.

It came to rest among trees and rocks on a steep slope, complicating rescue efforts.

Fire service commander Santi Lleonart described the location as difficult to access and said the bus was ‘in a very unstable position’.

Firefighters and rescue teams worked to secure the vehicle before evacuating those trapped inside.

Many passengers with minor injuries managed to climb out and make their way up the slope to the road. Those more seriously hurt required specialist rescue and evacuation.

Around 30 ground crews attended, supported by two medical helicopters and two fire service helicopters carrying mountain rescue teams.

Catalan health minister Olga Pane said the terrain made it difficult to establish whether anyone remained outside the coach.

Drones and search dogs were deployed around the wreckage, with officials warning that daylight would be needed to complete checks.

The weekend and public holiday shuttle is intended to reduce private car use in the park, which attracts large numbers of autumn visitors.

The bus had 65 passenger seats, according to the report, but some passengers were travelling standing in the aisle. The preliminary casualty count alone reached 83.

Families with children were among those aboard.