By Susan McFarland | Updated March 20, 2018
(UPI) — A package bomb headed for Austin, Texas, exploded early Tuesday at a FedEx facility near San Antonio, authorities said — maybe the latest attack from a serial bomber.
A FedEx employee suffered a concussion in the blast shortly after midnight at the Schertz, Texas, facility located about 15 miles northeast of San Antonio.
About 75 employees were working at the processing plant when the package exploded.
An FBI agent said the box was being mailed from Austin and was headed to Austin. Investigators said the explosion is likely linked to four other attacks this month. Joining the FBI and ATF are hundreds of law enforcement agents from across the state.
The package, which exploded as it was moving from an elevated conveyor belt to a lower section, was loaded with shrapnel consisting of nails and pieces of metal.
The explosion is the fifth in a recent string of package bombs in Austin that have killed two people and injured several others.
An explosion Sunday injured two men when a package left on their doorstep exploded. Police believe the device was likely triggered by a tripwire. Two men, ages 22 and 23, were injured by that bomb, but are expected to survive.
No arrests have been made related to the bombings, which killed two men.
Anthony Stephan House, 39, was killed March 2 in the first bombing attack. He was a father and a graduate of Texas State University.
Draylen Mason, 17, killed March 12 in the second of the bomb attacks, was recently accepted into the selective Butler School of Music at the University of Texas at Austin.
Sunday’s explosion occurred just hours after the FBI increased its reward for information to $100,000. Texas Crime Stoppers is offering an additional $15,000 for the bomber’s arrest and conviction.
The U.S. Department of Homeland Security on Tuesday announced a warning to travelers about the bombings and also enhanced screening procedures for all commercial flights to the United States.
“If you’re in the area, you should remain vigilant and follow the advice of local law enforcement authorities,” according to the announcement. “If you need more information about how this may affect your particular flight, contact your airline or travel company.”