At least four persons have been killed and scores injured when two passenger trains collided in the German state of Bavaria, police say.
The head-on crash happened near Bad Aibling, a spa town about 60km (37 miles) south-east of Munich.
One of the trains was derailed in the crash and several carriages were overturned, the BBC quoted German media as saying.
Police said rescue teams were trying to free people still trapped in the wreckage.
Regional police said in a tweet (in German) that four people were dead and about 100 injured, of whom 15 were in a critical condition and 40 seriously hurt.
There are fears that death toll could rise.
Another police spokesman, Stefan Sonntag, told Associated Press that the crash was the biggest accident Germany had seen in the region in years.
“We have many emergency doctors, ambulances and helicopters on the scene,” Sonntag said.
Regional train company Meridian said in a statement that “a tragic accident” had occurred on a single-track route between Rosenheim and Holzkirchen at about 07:00 local time (06:00 GMT).
Bernd Rosenbach, managing director of Bayerische Oberlandbahn which operates Meridian trains, told reporters: “The accident is a huge shock for us. We are doing everything we can to help the travellers, relatives and workers”.
Technical manager Fabian Amini added: “Our thanks go to the emergency services and workers who gave their help so quickly.”
Although the trains were carrying commuters, local carnival holidays meant no schoolchildren were on board, according to reports.
The cause of the collision is not yet known.