The city of Austin is on high alert after the fourth bomb in a month went off Sunday night and injured two men.
Both victims have been treated for non-life threatening injuries, officials said.
Police have advised residents of Travis County Neighborhood to stay home until 10 a.m. local time as authorities continued their investigation. The blast may be been triggered by a tripwire, Austin Police Chief Brian Manley said.
“We’re not believing that this was similar to previous ones, as in packages left on doorsteps. But instead, this was some type of suspicious package that was left on the side of the road, that detonated and injured these two men,” Manley said.
This is the fourth such blast in recent weeks, and Police believe Sunday’s incident is related to a string of unsolved package bombings which have killed two and injured two others.
Though motive has yet to be established, the first three bombs seemed to target people of color. The two men injured on Sunday were white, CNN reports.
The plea for residents to stay indoors comes as authorities increased the reward for information to $115,000, Manley said.
For now, Manley has directed residents stay away from anything that looks suspicious.
“We now need the community to have an extra level of vigilance and pay attention to any suspicious device — whether it be a package or a bag, a backpack — anything that looks out of place,” Manley said Monday. “Do not approach items like that.