ST. PAUL (WCCO) — They call it Operation Medicine Delivery. On Sunday, postal carriers will deliver a simulated supply of medicine in four zip codes.

They include 55101 and 55102 in St. Paul. Along with 55411 and 55422 in Minneapolis, Golden Valley and Robbinsdale.

The goal is aimed at getting the Twin Cities ready for a potential terrorist attack like an anthrax release.

This is the first full-scale test involving postal workers in the nation.