Two trains collided head-on Monday in western Switzerland, injuring 35 passengers, at least five of them seriously, police said.

The accident happened in Granges-pres-Marnand shortly before 7:00 pm (1700 GMT), according to local police.

An AFP reporter who arrived at the scene saw the wreckage of the train near the small station on the edge of the village of some 1,200 people.

The force of the crash was clear from the mangled engines of the trains, which were wrapped together.

One train had been bound for Lausanne, some 38 kilometres (24 miles) to the south, while the other was travelling north from the same city, officials said.

Around 45 people had been on board the trains, including the crew, a spokeswoman for national railway company CFF told AFP.

Frantic efforts continued into the night to free one of the driver, with whom there had been no contact since the crash.

Police spokesman Jean-Christophe Sauterel told AFP that heavy machinery had been brought in to try to get to the trapped driver faster.

As night fell, emergency workers set up massive arc-lights to help rescue operations continue.

Monday's collision on what is one of the most popular and safest rail networks in Europe was the latest in a series of rail accidents on the continent.

It comes in the wake of Wednesday's tragedy in the Spanish city of Santiago de Compostela which killed 79; and a crash near Paris two weeks ago that claimed seven lives.

Rescue workers, including medics and firefighters, had rushed to the scene from across the small-town Broye region where Granges-pres-Marnand lies, as well as from neighbouring cities.

A helicopter was scrambled by Switzerland's airborne REGA rescue service, known abroad for saving lives in the Alps.

The helicopter and ambulances rushed the five seriously injured individuals to a hospital in the nearby town of Payerne and south to the city of Lausanne.

In total, 23 people were taken to hospital, while the less seriously injured were treated on site by the emergency services and volunteer medics.

Traffic was interrupted between the towns of Moudon and Payerne, CFF said.

The company said both trains were operated by its regional service, a popular choice among commuters who work in the Lake Geneva hub of Lausanne.

Police said the northbound train was from the faster regional service, which in general stops at fewer destinations than the slower service that covers more local communities along the line.

Police experts, along with members of the Swiss accident investigation authority SESA, were on site to launch a probe into the causes of the crash, officials said.

The CFF spokeswoman told AFP that the two trains should have crossed at the station, thanks to a track system that allows them to pass one another.

It was not clear whether the collision could have been sparked by a delay to one of the trains, or one of them setting off too soon.

The accident echoed one in January at Neuhausen-am-Rheinfall in northern Switzerland, where two regional trains collided near a station.

Twenty-five people were slightly injured in that crash, caused by a failure to respect a signal.

Monday's crash was the most serious since one in Zurich in 2003 which injured 45 people.