VIENNA (AP) — It's not often that a swap site transaction results in the evacuation of an apartment house. But then again, how often is one of the objects being traded a live tank shell?

Austrian state broadcaster ORF says the shell was on offer as a dummy. It says police had to clear a Vienna apartment house of its residents and put up road blocks after establishing that it was in fact a fully functioning explosive.

Thursday's report said police were called to examine the shell by its new owner shortly after she had exchanged two bottles of wine and a picture frame for it on an online swap site.

ORF said the shell's previous owner had used it as a door stopper.  It also had been previously used in the pictured tank, but was never fired.

The report says both women face unspecified criminal charges.