A post office, a bank and several shops just outside of Denver have reopened following a bomb scare earlier Thursday after a suspicious package was discovered, ABC News in Denver reported.

The Douglas County bomb squad X-rayed the package and determined that it was an empty shipping container used to transport medicine that needs to be kept at a cooler temperature. The package --which was left overnight in the lobby of the post office in Elizabeth, Colo. -- was discovered Thursday morning by postal workers.

The post office and several businesses were evacuated around 8:30 a.m. and remained closed for about three and a half hours, according to ABC News.