A device exploded early Tuesday at a FedEx ground distribution facility in Texas injuring one person, which may be linked to a string of bombings that have rocked the state's capital this month, officials said.
Schertz Police Lt. Manny Casas told Fox San Antonio a medium-sized box was on the conveyor belt when the explosion occurred shortly after midnight. Casas said a woman was treated for a “possible sound injury” and was released.
FedEx said in a statement to Fox News that one employee is being treated for "minor injuries" after the single package exploded at the facility. Schertz is located 22 miles east of San Antonio and 73 miles south of Austin.
A police officer stops a vehicle at a check point in front of a FedEx distribution center where a package exploded, Tuesday, March 20, 2018, in Schertz, Texas. (AP Photo/Eric Gay)
"We are working closely with law enforcement in their investigation," the statement said. "We are not providing any additional specific information about this package at this time.”
Schertz police couldn’t immediately confirm what was in the package, but law enforcement officials told KSAT the medium-sized package contained metal shrapnel and nails and was headed to Austin when it exploded on a conveyor track.
The blast drew a large response from state, local and federal law enforcement agencies. Federal agents told the Associated Press the package is likely linked to attacks in Austin, while an ATF spokesperson told Fox News that officials are processing evidence at the scene and its "too early" to say if this fifth blast is related.
Officials at the scene after a blast was reported at a FedEx ground distribution facility in Schertz, Texas. (KABB-TV)
An ATF official told Fox News officials are looking at the latest blast due to the proximity to Austin and the other blasts. law enforcement agents are carefully combing the scene at the 100,000 square foot facility, the official added.
White House Press Secretary Sarah Sanders told "FOX & friends" on Tuesday that President Trump has "been made aware of the situation" in Texas after the latest blast.
"We are continue to work with local authorities on ground to do everything we can," she said.
Sanders added that federal authorities are working "closely" with local law enforcement to work to apprehend whoever is behind these "terrible acts."
Authorities in Austin were investigating another suspicious package at a FedEx facility close to Austin-Bergstrom International Airport on Tuesday. The Austin Fire Department said on Twitter that a hazardous materials investigation was taking place at the facility, but did not disclose additional information.
Authorities respond to a suspicious package at a FedEx facility in Austin on Tuesday. (FOX7)
A FedEx employee told Fox News she was coming to work at 6:30 a.m. when police told her they weren't letting anyone into the building, and that the facility was evacuated. The employee said the package that blew up in Schertz was supposed to be shipped to the Austin facility.
The blast in Schertz comes a day after authorities in Austin said a "serial bomber" is likely responsible for four explosions in Austin this month, the latest of which injured two people Sunday night after they crossed a trip wire possibly made with fishing line.
Austin Police Chief Brian Manley said at a news conference Monday that although the Sunday night bomb was linked to the three previous blasts, the latest bomb showed more sophistication as opposed to the previous three incidents, which involved package bombs left on people's doorsteps.
"We've seen a change in the method this suspect is using," he told reporters.
On Tuesday, Manley said authorities in Austin are "aware of the incident" in Schertz, and are "working closely on the investigation with our federal partners, Federal Bureau of Investigation and Bureau of Alcohol, Tobacco, Firearms and Explosives."
Frederick Milanowski, the special agent in charge for the Bureau of Alcohol, Tobacco and Firearms, said trip wire devices, possibly using fishing line, are triggered by victims applying any kind of pressure or tension.
"We are more concerned now. That is, people see something suspicious they stay away and contact law enforcement," he said.
The men injured Sunday night in the explosion in the southwestern Austin neighborhood of Travis Country, ages 22 and 23, are white, unlike the victims in the three earlier attacks, who were black or Hispanic.
A family member of one of the latest bombing victims in Austin told the AP on Monday the blast left what appeared to be nails stuck below his grandson's knees.
While authorities have not yet identified the victims of Sunday's explosion, William Grote said his grandson was one of the two people hurt in the blast.
Evidence markers can be seen at the site of Sunday's bombing in Austin, Texas. (KENS -TV)
"Well he and his friend were riding a bicycle about a block from their house and one of them was off the curb right in the street. The other one was on the sidewalk walking and it was so dark they couldn't tell and they tripped and set off this explosion, didn't see it," he told the AP. "It was a wire and it blew up "
Grote said the blast knocked "them both off their feet" and left them "bleeding profusely."
"You don't know what to think," he told the AP. "When something like this is happening. It's just uncalled for."
Sunday’s explosion was the fourth to rock Austin in less than three weeks. However, the three previous blasts occurred on the east side of the city.
The first was a package bomb that exploded at a northeast Austin home on March 2, killing 39-year-old Anthony Stephen House. Two more package bombs then exploded farther south on March 12, killing 17-year-old Draylen Mason, wounding his mother and injuring a 75-year-old woman.
A map shows the location of each of the four bombings in Austin. (Fox News/Bing)
As of Monday, the reward for information leading to an arrest in the deadly explosions had risen to $115,000. Manley said more than 500 officers, including federal agents, have conducted 236 interviews in following up 435 leads.
Fox News' Shira Bush, Jonathan Hunt, Madeline Rivera, and The Associated Press contributed to this report.
Ryan Gaydos is an editor for Fox News. Follow him on Twitter @RyanGaydos.