A bomb from the Second World War was found during construction work on a company site in Leuna (Saalekreis).
A spokeswoman for the district said in the evening that it was a 2.5 quintals American bomb with a rear fuse.
The ordnance should be defused on site on Thursday morning.
From around 9.45 a.m. and until it has been successfully disarmed, the railway line between the Merseburg and Großkorbetha stations will remain closed.