Aibling, Germany - Two commuter trains crashed head-on in southern Germany on Tuesday, killing at least nine people and injuring more than 100, in one of the country's deadliest rail accidents in years.
Hundreds of rescuers were scouring for more passengers trapped in the mangled wreckage in a wooded area near Bad Aibling, a spa town about 60 kilometres (40 miles) southeast of Munich.
At least two carriages from one train were overturned, while the front of the other was crushed. Blue, yellow and silver metal debris was strewn around the crash site next to a river in the southern state of Bavaria.
"We now have nine dead," said police spokesman Juergen Thalmeier. One person was still missing, likely trapped in the wreckage.
Eighteen people were seriously injured and 90 had light injuries, police said in a statement.
The two train drivers and two conductors were among those killed, local broadcaster Bayerischer Rundfunk reported.
German Chancellor Angela Merkel expressed shock at the news.
"I am dismayed and saddened by the serious train accident this morning at Bad Aibling," Merkel said in a statement.
"My sympathy goes out especially to the families of the nine people who have lost their lives." Transport Minister Alexander Dobrindt said the rail track was fitted with an automatic braking system aimed at preventing such crashes, and that investigators were proving if there had been "a technical problem or human error".
"One train was jammed into the other and the carriage of the second train was completely torn apart," he said.
Three black boxes on the trains should help shed light on the accident, he said, adding that two had already been recovered, and the third should be found in the course of the day.
The trains collided at high speed, and both drivers probably did not see each other until the last minute because the crash happened on a curve, said Dobrindt.
"At the moment we will have to wait (for the result of the investigation), everything else is speculation, and would be unhelpful and inappropriate," he said.
A passenger named as Patrick B. told local radio Rosenheim 24 that shortly after leaving the station of Kolbermoor, "the train suddenly braked, there was a loud noise and the light went out".
He said he "heard people shouting for help everywhere" and together with a young man, he opened the carriage door using the emergency system.
"We led passengers onto a slope, and only one man with a broken leg could not be helped out. Shortly after, the first emergency workers arrived." Some 700 firefighters, emergency services workers and police officers were deployed in the rescue operation, which was complicated because the forest crash site was difficult to access.
Rescuers focused on the impact area of the trains, using electric saws to cut through the mangled wreckage.
Underlining the difficulty of the emergency operation, mountain rescuer Joerg Becker told NTV: "The terrain is not only difficult to access but the large number of injured also requires a massive coordination effort between so many rescue and aid groups." About a dozen helicopters were also deployed, with television footage showing them waiting in a clearing outside the forest, from where rescuers were emerging with stretchers carrying the injured.
Besides the rail stretch, two nearby roads were also closed to traffic.
"The tragic accident occurred on the single-track route between Rosenheim and Holzkirchen this morning shortly after 7:00 am (0600 GMT)," regional rail company Meridian, a subsidiary of the French group Transdev, said in a statement.
"The accident is an enormous shock for us," said Bernd Rosenbusch, who heads the Bavarian rail company BOB that operates trains on the route.
"We will do everything to help travellers, their relatives and our employees."
Christian Schreyer, chief executive of Transdev, said: "We are deeply shocked and stunned that something like this could have happened. Our thoughts are with the victims and families of the victims".
After German rail was liberalised at the end of the 1990s, BOB - a subsidiary of Transdev, became one of the train operators competing with state-run Deutsche Bahn.
Although it has lost its monopoly operating status, Deutsche Bahn still owns the rail network.
The accident is believed to be Germany's first fatal train crash since April 2012, when three people were killed and 13 injured in a collision between two regional trains in the western city of Offenbach.
The country's deadliest post-war accident happened in 1998, when a high-speed ICE train linking Munich and Hamburg derailed in the northern town of Eschede, killing 101 people and injuring 88.