Manley said it wasn't clear whether an individual or group committed the attacks. He has tried to reach out to whoever is responsible, asking for a dialogue to prevent further harm to residents. But hours after the Austin police made a public appeal in the case Sunday, increasing the reward for information to $115,000, the fourth explosion occurred. The motive for the attacks also remains unclear, Manley said.

Source: Los Angeles Times March 20, 2018 10:13 UTC