Police say a wanted man assaulted a USPS worker with a firearm and stole $100,000 in the Bronx. Federal authorities are now also investigating the incident.

The 56-year-old postal worker was approached by the suspect in front of the post office on Castle Hill Avenue around 7 a.m. Tuesday, authorities say. The suspect struck her on the head with a gun, demanded her to open the building and afterwards the safe inside.

The suspect got away with approximately $100,000 and an unknown amount of money orders.

The worker was treated at the scene for minor injuries. 

Anyone with information on this robbery is asked to call the Postal Inspection Service at 212-330-5266.