German chemical company BASF says a World War II-era American bomb has been discovered at its main plant in Ludwigshafen, about 75 kilometers (47 miles) south of Frankfurt.

BASF says the 500-kilogram (1,100-pound) bomb was found Aug. 4 in the southern part of the plant, which comprises production sites and office buildings. A total of 35,000 people work at the Ludwigshafen site, which was a target for Allied bombers during WWII.

The company said in a statement Friday that the bomb will be defused on Sept. 26 and that it poses no threat to employees or the public.

BASF says a 6.5-meter (21-foot) pyramid of sandbags will be built around the bomb as a security measure.

Hundreds of unexploded bombs from WWII are found each year in Germany.