Updated at 11:45 a.m. ETA package that exploded at a FedEx Ground distribution facility near San Antonio was addressed to a location in Austin. It's the fifth explosion of a device either in Austin or meant to be delivered to the city."One person was treated and released at the scene" of the explosion early Tuesday, the Schertz Police Department said.Schertz Police Chief Michael Hansen said that the package blew up while it was on an automated conveyor and that a FedEx worker who was nearby "later complained of ringing in the ears.""We were very fortunate" that there weren't any other injuries, he added.The blast in Schertz follows a string of bombings in Austin. FBI spokeswoman Michelle Lee said, "We believe that the explosion is likely connected" to those earlier blasts.Officials said the facility was not the package's target."Several local news outlets report the package was coming from Austin and being sent to an Austin address," Nadia Hamdan of member station KUT in Austin reports. "The FedEx facility is about an hour southwest of the city."Providing an update on the serial bombing case to the Austin City Council on Tuesday, Austin Police Chief Brian Manley was asked about reports that the Schertz package had originated in southern Austin, at a FedEx location on Brodie Lane."I'm not confirming anything that we do not believe should be out in the media based on the integrity of the investigation," Manley said.Hours after the blast near San Antonio, Austin police headed to the scene of a suspicious package that was reported at 4107 McKinney Falls Rd. — an address that corresponds to a FedEx Ground facility in Austin. The city's fire department said a hazmat team was there to help with the investigation."There is an army of law enforcement folks that are here," Austin Mayor Steve Adler told NPR's David Greene. "Hundreds of federal agents, multiple federal agencies, hundreds of agents working on this outside of Austin and Texas."Adler added, "I'm confident they're going to figure out who's responsible for this and stop it."The package detonated at around 12:25 a.m. local time at a facility in Schertz, Texas, northeast of San Antonio, the FBI says.The investigation into the Schertz blast was slowed by the need to ensure the FedEx facility was safe, FBI Assistant Special Agent in Charge James Smith said at a midmorning update."We're going to be here for a little while," Smith said.Investigators said Monday that a "serial bomber" is behind the Austin attacks, which have killed two people and injured several others. After a blast on Sunday that was triggered by a tripwire, investigators said the culprit was likely more sophisticated than they had first realized.Investigators believe the Austin bombings are related, Manley said, "because of some of the specific components of these devices. We are sending all of the evidence to the ATF lab in Quantico, and they are conducting all of the post-blast analysis of the evidence that we have recovered.Those experts, Manley said, "are reconstructing these devices so that they understand what the firing mechanism is" and what explosive is being used.Police have urged Austin residents to report any suspicious packages. The Austin Police Department says it has received a total of 1,257 such calls since March 12 — including 420 in the 24 hours between 8 a.m. Monday and 8 a.m. Tuesday.The bombings have raised the question of whether the case can be more accurately seen as domestic terrorism or a hate crime — in part because the first victims of the bombs were people of color, including two black men who were killed.When asked how he sees the case, Adler said, "I certainly know there is significant fear and terror being felt by people in the community." He added that law enforcement is approaching the bombings with an open mind and exploring every possibility.It seems that Tuesday's explosion was not as dangerous as it might have been had it reached its target."[T]he package was moving from an elevated conveyor belt to a lower section when it exploded," reports CBS Austin.The package "contained shrapnel consisting of nails and pieces of metal, sources said," according to the CBS affiliate, which said the Schertz facility has 75 employees.FedEx released a statement about the blast in Schertz: