Six people have been hurt, one of them seriously, when a large carnival float caught fire at a parade in Kehl in southwestern Germany, police say.
One person suffered such severe burn injuries that he had to be taken to hospital in a rescue helicopter.
Several other people were injured, police said.
Kehl officials said the fire broke out in the interior of the float, which looked like a ship.
Police said the float was badly damaged.
To save themselves from the flames, several people jumped off the float and onto the street.
Police said the truck with the float trailer was badly damaged.
Local resident Jan Fritzsche described what happened: “We heard a detonation and then it suddenly started burning. Fire brigade, police and ambulance arrived straight away. The people were first evacuated here and then the fire was put out.”
The parade, which tens of thousands of people had turned out to watch, was stopped after the incident.
Kehl mayor Wolfram Britz rushed to the scene of the accident immediately after the fire department was alerted at 3.10pm.
Firefighters quickly extinguished the blaze.
The police have launched in investigation into the cause of the fire and suspect an explosion.
Kehl sits on the Rhine river opposite of the French city of Strasbourg.
Revellers were celebrating Fastnacht, a regional variant of carnival festivities.
With fearsome masks, colourful costumes, loud screaming and shrill music, so-called Narren (jesters) seek to drive out the winter.
A Christian festival, Fastnacht – which means the time or night just before the start of the Lent fasting period – is closely tied to customs and tradition, and was first officially documented in the Middle Ages.