Four people have been injured in an explosion caused by an old World War II bomb near a busy train station in the German city of Munich, police said.

Iran PressEurope: The explosion that happened after drilling during construction work near Donnersbergerbruecke station caused the bomb to go off on Wednesday, police said.

The force of the blast almost tore a seriously injured worker's leg off, German media outlet DW reports.

Doctors operated on him for four hours, reconstructing his leg. His condition was then listed as stable.

Bavarian Interior Minister Joachim Herrmann said workers accidentally hit the 250kg bomb while drilling.

No further information was available on the type of bomb involved but munitions dating back to World War II are not uncommon finds in Germany.

More than 70 years after the end of the war, about 2000 tonnes of live bombs and munitions are still discovered in the country each year. 219