AUSTIN, Texas >> Emergency teams were responding Tuesday night to another reported explosion in Texas’ capital, this one at a Goodwill store in the southern part of the city. The blasts happened in east Austin areas that predominantly have minority residents, and some in the area expressed concern the attacks might have been racially motivated

Police have not uncovered a motive and have not ruled out the possibility those bombings could be hate crimes. "The bomber also began to pick up the pace, using FedEx to mail out at least two packages, one that exploded early Tuesday on a conveyor belt at a FexEx sorting facility near San Antonio that left one worker with minor injuries.ATF technicians had already learned a lot about the mystery bomber by studying the thousands of pieces of metal, bolts, nails and triggering devices he used to build his arsenal. Lee said that although it is still early in the investigation, “it would be silly for us not to admit that we suspect it's related” to the four Austin bombings that have killed two people and injured four others since March 2. Investigators are trying to determine whether an explosion early Tuesday at a FedEx facility outside San Antonio is connected to four explosions that have rattled the Austin, Texas, area this month. He added that the person responsible for the bombings had previously been “very sophisticated in going around surveillance cameras.”

“They’ve got a couple of videos that could possibly be the person but they’re not sure at this point,” McCaul said. Key developments

• A FedEx spokesman, Jim McCluskey, said of the person who sent the package that exploded Tuesday, "The individual responsible also shipped a second package that has now been secured and turned over to law enforcement." As hundreds of law enforcement officers fanned out across the heart of Texas this month in the hunt for the Austin bomber, laboratory technicians with the federal Bureau of Alcohol, Tobacco, Firearms and Explosives hunched over thousands of tiny bomb fragments in a feverish race to rebuild the devices -- knowing they'd yield key clues about their creator.Although some of the bombs were fashioned into packages left on doorsteps and at least one was triggered by a tripwire planted alongside a street, agents were able to zero in on common parts used in all the devices to discover key clues about where they were purchased and, eventually, who bought them, officials said. JUST WATCHED Austin police: We're dealing with a serial bomber Replay More Videos ... MUST WATCH Austin police: We're dealing with a serial bomber 01:13

"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," he said Monday.
A bomb detonates overnight at a FedEx facility in San Antonio, Texas, United States. The FBI believes the bombing is linked to the other bombings in the area. The ATF reports that there were no serious injuries. Both the bomb's point of origin and intended destination were in Austin.