A train derailed near a Bavarian Alpine resort in southern Germany on Friday, killing at least four people and injuring dozens in a region gearing up to host the G7 summit in late June.
Several carriages of the red-coloured local train were lying on their sides on a grassy area next to a highway.
Rescuers stood on the top-facing side of the carriages, using ladders to climb into the waggons to reach trapped passengers.
"In the serious train accident, as of 3:32 pm (1532 GMT), four people were fatally injured," said police in a statement.
"Around 30 passengers were injured, 15 of them so seriously that they have had to be admitted to nearby hospitals," they said, adding that a huge rescue operation was underway.
Bavaria's interior minister Joachim Herrmann said three of the victims were found dead, while a fourth succumbed to her injuries on the way to the hospital.
Chancellor Olaf Scholz voiced shock at the accident and said his sympathy was with families of the victims.
The accident came as rail officials were nervously watching if a new nine-euro ($10) monthly public transport ticket valid across Germany would lead to packed trains over the bank holiday weekend.
- Technical fault? -
Stefan Sonntag of Upper Bavaria's police force said the regional train was "very crowded and many people were using it, hence the high number of injured".
School holidays were also starting from Saturday in the two southern German regions Baden-Wuerttemberg and Bavaria, raising fears children may count among the injured.
Images carried by German television showed teenagers on the rails, apparently after having managed to climb out of the train.
The train had just left Garmisch-Partenkirchen for Munich, when the accident took place in the Burgrain district of the resort town, just past midday.
Part of the route between Munich and Garmisch-Partenkirchen has been blocked off and traffic diverted, said German rail operator Deutsche Bahn, which was not yet able to provide a reason for the accident.
But Bavaria's transport minister Christian Bernreiter told regional broadcaster BR that the accident may have been a result of a technical fault.
"There were no third parties involved here, so one must assume that some technical reason -- either on the vehicle or on the rail -- was the cause," he said.
Even as Germany launched the heavily subsidised monthly transport ticket from June for three months to provide inflation relief, Deutsche Bahn had warned that heavy investments would be needed to modernise the tracks.
- Rescue operation -
"We have a dilemma that is hardly possible to resolve in the short-term -- to grow and modernise at the same time," said Richard Lutz, Deutsche Bahn chief on Monday.
Popular mountain resort Garmisch-Partenkirchen and the surrounding region have begun preparations to host the G7 summit of world leaders later this month.
From June 26-28, the heads of state and government including US President Joe Biden are due to meet at Schloss Elmau -- 11 kilometres (seven miles) from Garmisch-Partenkirchen.
Police and soldiers who had been deployed to prepare and secure the site ahead of the summit have now also been enlisted to help in the rescue operation.
Three helicopters from Austria's Tyrol region were scrambled to the scene to provide first aid, according to media reports.
Germany's deadliest rail accident happened in 1998 when a high-speed train operated by state-owned Deutsche Bahn derailed in Eschede in Lower Saxony, killing 101 people.
The most recent fatal crash took place on February 14, 2022, when one person was killed and 14 others hurt in a collision between two local trains near Munich.
In 2017, a passenger train and a stationary freight train collided near the western city of Duesseldorf injuring 41 people.