With the revelation that the three package explosions are connected, Austin police are issuing a warning to people who see packages outside of their home.
Two separate explosions occurred Monday in Austin, capital of the state of Texas, killing a teenager and wounding two women.
Two of the blasts happened within hours of each other, sending police scrambling from one crime scene to the next.
Detectives are linking the incidents to a similar bombing in the city earlier in March, in which a 39-year-old man was killed.
Austin-Travis County emergency medical services tweeted that the later blast left a woman in her 70s with potentially life-threatening injuries and that a second woman in her 80s was being treated for an unrelated medical issue.
On Monday, the 17-year-old found a package outside his house and brought it into the kitchen, where it exploded, Manley said.
Three exploding packages in ten days, leaving two people dead.
Manley said authorities know what kind of explosive devices were used, but they are not revealing details to preserve the integrity of the investigation.
Regarding unexpected or suspicious packages you may find in the front of your home, Chief Manley said, "Under no circumstance should use touch them, move them or handle them in any way".
"It's not time to panic", Manley said.
"The damage is significant, and there's a lot of evidence that needs to be collected", Manley said. "It's just a regular family neighborhood", he said. The March 2 blast was initially investigated as a suspicious death, but is now viewed as a homicide. "There's a certain level of skill and sophistication that whoever is doing this has".
After the March 2 explosion, Austin police said they had no indication the blast was related to terrorism. Police said just before noon, they received several calls reporting an explosion in the 6700 block of Galindo Street, near East Riverside Drive and Montopolis Drive. But he said it's not clear the victims knew each other directly, or if they were specifically targeted.
Of the three explosions, two of them happened in the early morning hours. Guerrero says he climbed onto his roof where he could see police walking up to one of his neighbors' homes.
Federal investigators were helping local authorities in the probe.
"High explosives are supposed to be stored properly and securely, so it would be a little more hard to obtain high explosives - unless you're in a job that gives you access to them", Key said.
In the awake of the explosions, Texas governor's office is offering a reward of up to 15,000 USA dollars for any information that leads to the arrest or identification of those involved.
Manley said anyone receiving a package they don't recognize should call 911.
The ATF is processing evidence from the first device at its lab and evidence from the second device will also be sent to an ATF lab for consistency.