The explosive device that injured two men in Austin on Sunday night appears to have been a different—and even more worrying—kind of device than the package bombs that killed two people earlier this month, police say. Interim Police Chief Brian Manley said early Monday that investigators believe the device may have been triggered by a tripwire, the Austin American-Statesman reports. "It is very possible that this device was a device activated by someone either handling, kicking, or coming in contact with a tripwire that activated the device," the chief said. "That changes things." The three package bombs earlier this month were left on doorsteps and went off either when the package was moved or when it was opened.
Manley said the two injured men were apparently riding or pushing bikes Sunday night when a device at the side of the road exploded. "Our safety message to this point has been involving the handling of packages, and telling this community 'Do not handle packages, do not pick up packages, do not disturb packages,'" the chief said. "We now need to have an extra level of vigilance and pay attention to any suspicious device, whether it be a package, a bag, a backpack, anything that looks out of place and please do not approach it." He said police believe the latest device is connected to the previous three, but the scene is still being investigated, the BBC reports. Hours before the latest blast, Manley addressed the bomber, saying police are listening and "want to understand what brought you to this point." (Read more Austin stories.)