Shrewsbury police are searching for a suspect who robbed a post office, injuring an officer early Monday evening. The incident occurred at the U.S. Post Office on Watson Road. According to the Shrewsbury Police Department, the incident started with an armed robbery that took place on the loading dock of the post office. Police did not say what, if anything, was taken. The injured officer was transported to a hospital and was later released with minor injuries. The Shrewsbury Police Department is urging anyone with information about the suspect to come forward. The incident is still under investigation.