“Thirty passengers were taken to hospitals, some with serious injuries. The others are believed to have died in the burning tour bus,” which had been carrying 48 people, police said in a statement.
There was “only a glimmer of hope” that 18 people missing after the collision would be found alive outside the coach, which was completely gutted, police spokesman Jürgen Stadter told rolling news channel NTV. Police had originally said that 17 people were missing.
“Maybe someone ran away in shock,” Stadter said.
The bus carrying 46 passengers and two drivers rammed into the trailer in a traffic jam on the motorway A9 close to the Bavarian town of Stammbach. The crash shortly after 7 am sent the bus up in flames, with television images showing only the charred skeleton of the vehicle remaining.
The bus was carrying a tour group from eastern Germany’s Saxony state, police said, and it was bound for Nuremberg from Lausitz, according to Bild newspaper.
It was unclear what kind of tour group the bus was carrying.
Chancellor Angela Merkel voiced “great dismay” over Monday’s bus crash.
“Our thoughts go to the victims and their family members, as well as to the injured. We hope that those who have been rescued will recover from their injuries,” said her spokesman Steffen Seibert.
The accident struck near the town Bayreuth, which draws thousands of classical music lovers every summer to its opera festival.
The region close to the Czech border is also dotted with spas and castles, and the A9 is a trunk motorway leading to many popular summer holiday spots.
Some 200 emergency workers were deployed to the site, including firefighters, rescue workers and police, while south-bound traffic on the motorway remained blocked.
Those hurt were being flown by rescue helicopters to hospitals, many with life-threatening injuries.
If those missing are confirmed killed, the accident at the start of the summer holiday season would be one of the worst to hit Germany.
Among the deadliest in recent years was a collision in June 2007, when 13 people were killed as their tour bus drove off the road and plunged several metres down a slope in eastern Germany’s Saxony-Anhalt state.
In September 1992, 21 people died when a bus swerved out of its lane and struck a truck before ramming into the road divider in the southern Black Forest region, a key tourist destination.
Across Europe, the last such fatal accident struck on January 21 in Italy, when an accident involving a Hungarian bus carrying teenagers left 16 dead.
In France, a head-on crash in October 2015 between a truck and a bus carrying pensioners claimed 43 lives as both vehicles burst into flames.