March 20 (UPI) -- A blast at a Goodwill store in South Austin Tuesday evening is not related to a series of package bombs that exploded in the area this month, authorities said.
Austin police department Assistant Chief Eli Reyes said officers determined a Goodwill employee found a box of donations containing two "artillery simulators," one of which initiated when a second employee handled it.
"This was not an explosive device, this incident is not related to any of the other incidents we've had here in Austin," Reyes said.
Police are reviewing video footage to determine who dropped the objects off or if they intended to harm someone. Reyes said similar military mementos are often dropped off by family members who are unsure how to dispose of them.
The Bureau of Alcohol, Tobacco, Firearms and Explosives also released a statement saying the incident didn't appear to be related to the six other bombs -- five of which detonated, one of which did not -- police said are linked in and around the city since the beginning of March.
Austin-Travis EMS said officials transported a man in his 30s to St. David's South Austin Medical Center with non-life-threatening injuries following the Goodwill incident.
Earlier in the day, Sunset Valley police department said the FBI is investigating the possibility the six confirmed related bombs are linked to a private package delivery office in Sunset Valley, an enclave in the capital of Texas.
The police department said there were no known public safety threats to Sunset Valley residents or others in the area, but urged residents to report any suspicious packages, items, or occurrences
Earlier Tuesday, a package bomb headed for Austin exploded at a FedEx sorting facility near San Antonio. Police later found another package containing an explosive device at another FedEx facility near the Austin-Bergstrom International Airport.
A FedEx employee sustained 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.
Police so far are investigating a total of six bombs or suspicious packages this month. In addition to the one that exploded in Schertz and the suspicious package found at the Austin FedEx facility Monday:
-- On March 2, Anthony Stephan House, 39, died in the first bombing attack in East Austin. He was a father and a graduate of Texas State University.
-- On March 12, Draylen Mason, 17, died and his mother, Shamika Wilson, was injured in the second of the bomb attacks also in East Austin. Draylen was recently accepted into the selective Butler School of Music at the University of Texas at Austin.
-- On March 12, Esperanza "Hope" Herrera, 75, sustained injuries when a package left outside her East Austin exploded at her home.
-- On Sunday, an explosion injured two men when a package left on their doorstep exploded. Police believe the device was likely triggered by a tripwire. The two men, ages 22 and 23, were expected to survive.
Austin interim Police Chief Brian Manley said investigators believe the first four bombs are connected because of similar components and the Schertz bomb could be related. Manley tweeted a statement reminding residents to remain "vigilant."
An FBI agent said the box that exploded Monday was being mailed from Austin and was headed to Austin. 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.
Joining the FBI and ATF are hundreds of law enforcement agents from across the state.
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."