Eleven people have been injured after a Swiss mountain train ran into a landslide in the Alps, derailing three train cars and sending one carriage into a ravine, police said.

Officials said on Wednesday that five people were seriously injured and six slightly hurt in the accident on the line between the mountain resort of St. Moritz and the eastern city of Chur.

Terrified passengers crowded into the rear of another carriage in a bid to prevent it from tipping over the edge.

"We all rushed to the back of the carriage to put all of our weight there, so that it didn't tip into the abyss," passenger Stevens Bockor was quoted as saying by news website 20Minuten.

Photos in Swiss media showed one of the bright-red carriages lying precariously on the ravine's slope, some 10 metres from the track, its fall apparently blocked by the dense pine forest.

Another carriage remained perched on the edge of the track, half of it hanging over the ravine.

In front of it was a broad swathe of mud and rock, which had cut across the hillside rail line.

Landslide debris

The eight-carriage train, operated by eastern Swiss regional company Rhaetische Bahn, derailed at around 10:45 GMT on an isolated stretch of track in the forest near the picturesque village of Tiefencastel.

Rhaetische Bahn spokesman Simon Rageth told AFP news agency that a landslide was to blame.

The landslide did not appear to have struck the carriage directly, with regional police saying the train had run into the debris.

"There were around 200 people on the train," police said, adding that those who were unhurt made their way down the line to Tiefencastel, where paramedics treated them for shock.

The region has been lashed by heavy rain in recent days and waterlogged earth is a common cause of landslides.

Last month, storms sparked landslides that blocked several lines, including between the capital Bern and the western city of Fribourg, as well as from Montreux on the shores of Lake Geneva to the mountain town of Zweisimmen. 

July's rain also flooded another line near Bern and forced the closure of several roads.

In July 2013, a head-on collision blamed on signal-jumping killed a driver and injured 25 people near Payerne in western Switzerland.

Wednesday's accident comes just two days after three Israeli tourists died and five were seriously injured when a train hit their minibus at an ungated level crossing in the central Swiss Alps.

Source: Agencies