Texas city rocked by fourth bomb blast Police in Austin, Texas, are warning that a fourth device that exploded in the city, injuring two men, may be connected to three parcel bombs that have killed or injured four other people since early March Mar 2: Parcel bomb left on front porch kills Anthony Stephan House, 39 Mar 12: Draylen William Mason, 17, killed after bringing package inside home. Explosion also critically injures his mother Mar 12: Hispanic woman, Esperanza Morena Herrera, 75, injured by another package Mar 18: Two men in their 20s injured after finding suspicious device on side of road. Bomb possibly activated by tripwire Both men killed were African-American, police have not ruled out racism as possible motive. Reward of $115,000 offered for information TEXAS Austin 320km 200 miles University of Texas at Austin AUSTIN Capitol Building 1 2 3 4 35 4km 2.5 miles Source: Austin Police Department Pictures: FBI © GRAPHIC NEWS