A German hospital is using a graphic picture of a mangled hand to warn people against buying or using illegal firecrackers.

Klinikum Dortmund posted the photo on Wednesday, ahead of New Year's celebrations when Germans traditionally set off large quantities of fireworks.

Hospital spokesman Marc Raschke says the image shows a patient whose thumb and two fingers were blown off by a powerful firecracker two years ago.

Raschke says the Dortmund hospital typically treats two to four such injuries each year, and the picture was "one of the more harmless ones."

Germans spend an estimated 100 million euros ($104 million) on New Year's fireworks annually.

Illegal imported fireworks and improper use are blamed for the majority of serious injuries and deaths.