U.S. federal authorities investigated an explosion early Tuesday at a FedEx Corp. facility in Schertz, Texas, following a series of bombs that exploded this month in Austin and left two people dead.

The Federal Bureau of Investigation and the Bureau of Alcohol, Tobacco, Firearms and Explosives responded to the incident at the FedEx sorting location, according to tweets from the agencies. One FedEx employee was being treated for minor injuries, the company said by email. The Memphis, Tennessee-based company said it was working with law enforcement.

The explosion in Schertz came after four bombs about 65 miles away in Austin killed two people and wounded four others since March 2. The first three devices were package bombs and the fourth used a more sophisticated tripwire trigger.

While the Schertz investigation was just getting started, “it would be silly for us not to admit that we suspect it’s related” to the Austin bombings, FBI Special Agent Michelle Lee said, according to the Associated Press.