At least nine people were killed and scores injured after two commuter trains collided at high speed in southern Germany early Tuesday, officials said.

A massive rescue operation — involving more than 500 personnel and some 14 helicopters — was launched following the crash near the town of Bad Aibling in Bavaria at around 7 a.m. local time (1 a.m. ET).

German officials told a press conference two passengers were still missing more than six hours after the incident. They said there were around 150 people on both trains — the same number police earlier said had been injured.

The trains were traveling around a curve at around 60 mph on a single-track route when they collided, German Transport Minister Alexander Dobrindt told reporters.

“One train more or less plowed into the other,” he said, adding that the curve meant it was unlikely the train drivers saw each other.

He said the railway was equipped with a safety mechanism that should have forced the trains to automatically brake, but that it was too soon to say “what kind of effect it had in this case” and that crews were still attempting to recover the trains’ black boxes.

“I just visited the crash site and it is a scary picture,” Dobrindt said.

Police spokesman Markus Wessner earlier told NBC News that at least one of the trains derailed in the incident between Rosenheim and Bad Aibling.

Image: Trains collide in Germany

Image: Trains collide in Germany

Both trains were on running on the so-called Meridian line.

“The accident is a big shock for us,” said Bernd Rosenbusch, chief executive of train operator Bayerischen Oberlandbahn.

Bayerischen Oberlandbahn’s technical CEO Fabian Amini said in a statement that teams “were on location quickly and were able to get a picture of the collision.”

“We thank the rescue services and staff who have helped so quickly,” Amini added.

All trains on the line have been suspended and replaced with bus services, according to the firm.

The crash site was in a hard-to-reach wooded area next to the river Mangall. Rescue helicopters could be seen airlifting casualties away from the wreckage for treatment.

The local blood donation center based in Munich, around 30 miles away, issued a statement urging people to give blood after the “tragic train accident … increased the need of life saving blood donations.”

Justice Minister Heiko Maas thanked rescue teams in a message posted on Twitter.

“Very bad news from #badaibling,” he wrote. “Our thoughts are with the victims + injured.”

Image: Trains collide in Germany

Image: Trains collide in Germany