Three circles, forming an impressive Venn diagram, appeared overnight near the railway crossing between Guntmadingen and Löhninge, online news site 20 Minuten reported.
“We do not know how the crop circle was made, nor who made it,” a spokesman for the Schaffhausen cantonal police told the website.
The damage to the wheat field caused by the crop circles is estimated at several hundred francs. The police are looking for anyone who might have seen the mysterious mowers at work.
This is the second circle discovered in the region in the past week and police are now calling for witnesses to come forward.
On Saturday, a man who had climbed a hill in Büsingen, a tiny German enclave, looked down to find a huge 20-metre circle visible below.
“How it got there, I just can’t figure out,” the bemused circle spotter told the newspaper.