An explosion tore through a quiet Austin, Tx., neighborhood Sunday night, sending two men to the hospital with serious injuries and heightening worries that a bomber is targeting the city’s residents. “We are clearly dealing with what we expect to be a serial bomber at this point,” said interim Austin Police Chief Brian Manley. Shortly after midnight, about 15 federal agents were walking side-by-side near the entrance to a subdivision shining flashlights on the road searching for clues. Manley said it was possible that a trip-wire triggered the explosion, a departure from the three prior bombs that were all inside packages, reports the Austin American-Statesman.
Some neighbors reported they had been told the explosion was the result of a trip wire. Manley cautioned residents that they need to be even more vigilant. “It is very possible that this device was … activated by someone either handling, kicking or coming in contact with a tripwire that activated the device,” he said. Police had been advising residents, “Do not handle packages, do not pick up packages, do not disturb packages,” Manley 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.” In Sunday’s case, there was a suspicious package left on the side of the road, and the victims were either riding or pushing bikes when it went off. “The device’s success, despite significantly different design, further suggests that the bombmaker behind these attacks is an accomplished one, and has likely to have received some training, perhaps as a military or police explosive ordnance disposal technician,” said Statfor Threat Lens, a think tank, CNN reports.