Eighteen people died when their tour bus collided with a lorry and burst into flames on the A9 motorway in southern Germany, police say.
Another 30 on the bus were hurt and two of them were fighting for their lives.
The bus was carrying a group of German pensioners at the time of the fire near Stammbach in northern Bavaria.
Bavarian Interior Minister Joachim Herrmann said rescuers were delayed by “gawpers” driving slowly and by the intensity of the blaze.
The cause of the fire is unknown. Traffic was reportedly moving slowly at the time and the collision between the two vehicles was not described as a major crash.
The lorry’s trailer was also incinerated and the burnt-out wreck ended up a short distance ahead of the bus. The German news website Frankenpost reports that it was carrying mattresses and pillows.
The lorry driver was unharmed and told police the bus had gone into the back of his vehicle and burst into flames, it said.
There were 46 passengers and two drivers on the bus. The bus driver was among those killed. The passengers were men and women aged 66 to 81, heading to Lake Garda in Italy for a holiday.
Some of the passengers had got on the bus at Dresden station in the eastern state of Saxony. According to local media in Saxony, the bus had earlier picked up passengers elsewhere in Saxony and also in Brandenburg in the early hours of Monday before going to Dresden and then south-west towards Nuremberg.
By mid-afternoon forensic teams had recovered the charred remains of 15 people and police confirmed that 18 had died.
Firefighters reached the scene within 10 minutes of the accident but were driven back by the intensity of the fire. “Only steel parts are recognisable so you can understand what that meant for the people in this bus,” said German Transport Minister Alexander Dobrindt.
Motoring safety expert Hans-Ulrich Sander suggested that the fuel line that ran under the bus may have ruptured, prompting the fire to spread fast.
Five rescue helicopters joined emergency workers at the scene.
Chancellor Angela Merkel said she was distressed by the accident and expressed sympathy for the injured and bereaved relatives.
She thanked the rescuers for looking after people “in an appalling situation”.