One person was killed and several were injured when a car drove into a crowd of people in the western German city of Mannheim, a police spokesperson said on Monday.
The car's driver has been detained, but it is unclear whether there are other suspects, the spokesperson added.
Police are appealing to the public to avoid the area.
The incident occurred as crowds gathered in cities across western Germany's Rhineland for parades to mark the carnival season.
A black SUV drove at high speed into a group of people, travelling from the centrally located Paradeplatz square towards the city's landmark water tower, local media reported.
Security has been a key concern in Germany following a string of violent attacks in recent weeks, including deadly car rammings in Magdeburg in December and in Munich last month, as well as a stabbing in Mannheim in May 2024.
Police are on high alert for this year's carnival parades after social media accounts connected to the Islamic State militant group called for attacks on the events in Cologne and Nuremberg.
