At least 30 people, most of them school children, were injured Monday when a train engine collided with carriages full of passengers at a station in the Swiss Alps, police and media said.

"No one is in critical condition," said a spokeswoman for the regional police in the Swiss canton of Uri.

Police initially said 27 people had been hurt.

Around 100 people were onboard when the accident happened shortly before midday, including three school classes counting 65 primary and secondary school students, the Swiss daily Blick reported.

Eighteen of those injured were children, it said.

The accident happened shortly as a train run by the Matterhorn-Gotthard rail company, made up of a locomotive and five carriages, attempted a manoeuvre at Andermatt station.

The locomotive was supposed to move to a parallel track to move from the back of the train to the front, and allow the train to head back towards the Alpine resort of Disentis.

But Jan Barwalde, a spokesman for the rail company told AFP something had gone wrong and the locomotive had slammed into the carriages.

"For some reason, the locomotive drove into the convoy it had just detached from, instead of moving onto the parallel track," he said.

He said the locomotive had been travelling at a speed of only 15 to 20 kilometres per hour (9-12 miles per hour), and there appeared to be very little material damage.

But the effect was nonetheless dramatic for the school children, many of whom were heading to a camp.

"We were just getting into the train when there was a jerk," 32-year-old secondary school teacher Chantal Michel told Blick.

She said some students who were on the stairs lifting suitcases into the train when the accident happened had fallen.

Twenty-five of those injured had been taken to hospital, but most were quickly released.

Teacher Andre Kobelt told Blick that one child was being kept in hospital overnight with a suspected concussion.

Three rescue helicopters and around a dozen ambulances were sent to the scene, Swiss media reported.

The regional police and the Swiss Transportation Safety Investigation Board have opened an investigation into the circumstances surrounding the accident.

Source: AFP