>> reporter: authorities here also went on to say the two victims from sunday night's explosion, two college age men, they believe were riding bikes or pushing bikes past the package left on the side of the residential street. that is why they believe a possible trip wire was used in the explosion. those two victims taken to a local hospital where they are treated. the injuries appear not to be life threatening as this point. it is interesting that just a few hours before this latest explosion, the authorities in austin came out to raise the reward to $115,000. the police chief made a direct plea to the person or persons behind the attacks urging whoever the culprits are to get in touch with them. they believe there is a message they are trying to send with the explosions and they want whoever is behind this to reach out to them so they can speak with them to understand what they are