Last night, a bomb meant for Austin, Texas exploded at a FedEx facility in Schertz, Texas. This is the fifth in a series of deadly bombs that have targeted Austin, the capital of the state.

The first three bombs were in packages delivered to people's homes, resulting in two deaths and injuries to two more people. The fourth bomb was detonated by a tripwire and seriously injured two men.

The first package exploded March 2, killing Anthony Stephan House, 39, when he picked up a package on the front porch of his northeast Austin home. The second bomb went off March 12 inside a home in east Austin. Draylen Mason, 17, was killed and his mother was hospitalized. The third blast came a short time later in a neighborhood south of downtown. A 75-year-old woman picked up a package on her front porch when it exploded, seriously injuring her. The last Austin blast occurred late Sunday, when a blast, possibly set off by a tripwire, injured two men in southwest Austin.

The first three attacks involved suspicious packages left on doorsteps in Austin. The package Sunday apparently was left on the side of a road in the city. The latest explosion took place at a FedEx facility about 65 miles from Austin.  (source)

Each bomb has been somewhat different, and increasingly sophisticated.  The Washington Post reports:

Police have declined to describe the bombs in detail, saying only that they appear to be the sophisticated work of a person or people who know what they are doing — and noting that the bombmaker has been able to assemble and deliver the devices without setting them off. After telling residents to remain wary of unexpected or suspicious packages, authorities are urging broader caution.

"We're even more concerned now that if people see something suspicious, they just stay away from it altogether and contact law enforcement," said Fred Milanowski, special agent in charge of the Houston division of the Bureau of Alcohol, Tobacco, Firearms and Explosives. "Because if they move that package or if they step on that tripwire, it's likely to detonate."